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Book Review: The Giessen Raw Food Study by Carola Strassner

Dissertation on raw food from the 1990s shows mistakes that can be made with this diet. The target audience is specialists. Has a rather negative tone.

Collage book "Die Giessener Rohkost-Studie" by Carola Strassner with text statement on the right.© CC-by-sa 2.0, Collage Catalina Sparleanu, PhD, Foundation Diet and Health Switzerland


This dissertation examines the nutrition and health habits of people following a raw food diet in Germany in the 1990s — however, the persons responsible at Justus Liebig University Giessen may have been biased and/or inexperienced. An interesting and impressive amount of data was accumulated.

The findings show us mistakes that people on a raw food diet can make. This tells us something about those who describe themselves as raw foodists (minimum 70 % raw food), but not a lot about a "proper" raw food diet.

There is noticeable negative bias on the part of the participants. It is not the task of this type of study to give readers advice on raw food, so we should not expect this.

The book is a great find for those interested in reading about nutrition in detail, but the target audience is not the consumer. My book review is accordingly quite challenging to read.

1. Summary

JLU Giessen conducted a wide-scale study on raw food. The study was under the direction of the dean Dr. Elmar Schlich, analyzed by Carola Strassner for her dissertation, and published as a book in 1998.

Contents, blurb and remarks

Note: The chapter titles and all quotations in italics are translated from the original German.


The table of contents takes up five pages and is followed by six pages of indexes for pictures, graphs, tables, and abbreviations. These are the titles of the actual chapters:

  • Adequate Protein Supply from Raw Food? A Literature Review.
  • Study Design of the Giessen Raw Food Study (p. 61)
  • Instruments and Methodology (p. 66)
  • Descriptive Results and Discussion (p. 81)
  • Results and Discussion of the Energy and Protein Status (p. 100)
  • Closing Remarks (p. 163)
  • Conclusion (p. 163)
  • Summary (p. 166)
  • Bibliography (pp. 168–194)

This is followed by an appendix that contains a definition of raw food, a list of diplom theses on the subject of raw food (p. 197), and additional appendixes and tables. On page 210, you can review copies of the questionnaires and on page 238 there is a list of 17 publications based on the Giessen Raw Food Study as well as acknowledgements and the author’s impressive resume.


Even nutrition specialists can get lost in the jungle of dietetics. Is it best to eat a primarily raw food diet? At what percentage of raw food should a person on a raw food diet be concerned about getting enough nutrients?

These and many other questions are discussed by nutrition specialist CAROLA STRASSNER in her thorough study of raw food.

She provides a detailed statistical analysis of the types of food consumed by the raw foodists and their state of health.

The author also addresses the problem of malnutrition in detail — especially in terms of protein supply — drawing on data from developing countries, anorexics, and chronically ill individuals. Without adhering to any dogma, she describes the current state of knowledge concerning this important issue.

To show that certain passages were not written by me or if I cite views that I don’t agree with, I often quote points that I find to be particularly important. These are always in italics and quotation marks.

The majority of the other sections are summaries of the book content and not interpretations of my own — if this is not the case, I state specifically that a certain section contains my own comments (e.g., in “About the study,” “The myths about plant protein,” and “My closing remarks”).

I wrote this book review in 2001. And then in February 2014 I decided to update it. I added boxes with images to provide more variety and to better set apart my own observations. This is similar to the structure of the book reviews on Salt Sugar Fat or Lies Lobbies Food.

The book is currently only available in German under the title Ernähren sich Rohköstler gesünder? (Is a raw food diet healthier?) and the subtitle Die Giessener Rohkost-Studie (The Giessen raw food study), published by Verlag für Medizin und Gesundheit (Publisher for medicine and health), 1998, ISBN 3-932977-04-1.

My preliminary remarks:

The dissertation concludes with the following sentence: Based on the results of this study, we do not recommend a pure raw food diet, particularly in the case of at-risk groups such as pregnant women, nursing mothers, children, and the elderly [217-164].

It is not surprising that this was the conclusion since the objective and purpose of the study was most likely to oppose a pure raw food diet.

The work could also have been an analysis of the situation, from which further helpful instructions and tips could have resulted.

Statistics show that people need advice for every type of diet form, including a raw food diet. This is the very reason why I created the website

The impartiality of the individuals who conduct and review studies (in this case Dr. C. Leitzmann and Dr. H. Laube) is always questionable. I also assume that even Ms. Strassner was not entirely free of her own expectations regarding the final outcome or that she was influenced by the expectations of those around her. This is why I cannot just dismiss the views of the participants as has been done in some other books on raw food.

Science almost always needs quite some time before contradictory or new insights become accepted

Unfortunately, we cannot really expect things to have taken a different course as science almost always needs quite some time before contradictory or new insights become accepted.

A good but tragic example is Ignaz Semmelweiss proposal that physicians practice handwashing, an idea he advocated in the German-speaking countries starting in 1847. For over 20 years, his colleagues responded only with mockery, and Semmelweis did not live to see the introduction of hygiene practices. He was taken to a mental hospital, where he soon thereafter was beaten to death by a guard. Dr. Semmelweis died when he was 47 years old. Today, this reflex-like tendency to object new evidence is called the Semmelweis reflex.

Based on knowledge about bacteria established by Louis Pasteur (and Casimir Davaine, 1863), Joseph Lister was the first physician to successfully introduce hygiene practices. He did so in 1867.

It is true that new or different findings turn out to be incorrect more often than they prove valid and are fully accepted in science. But I am surprised by statements such as: A moderate raw food diet supplemented with foods such as whole grain bread or other whole grain products and animal products — such as dairy products — MIGHT be possible for healthy adults with sufficient knowledge of nutrition [217-161].

However, see this book review on the harmfulness of milk.

This raises the following question for me: Why would a person who is eating exactly what the “scientific trend” recommends, that is “as much raw food as possible” plus whole grain and animal products need to obtain a “sufficient understanding of nutrition” in order to eat a hopefully healthy diet?

Cynicism is the wrong way to achieve positive results. But the above cynical question serves to illustrate how this study maintained a one-sided view. The study could not come out as “pro raw food.” Nor is it helpful for raw foodists, but that wasn’t the study’s purpose.

Photo "Das neue Rohkostbuch" by Lisa Mar, 1973 was my very first recipe book for raw food.© CC-by-sa 2.0, Lisa Mar

In 1978 I was diagnosed with a “rare B-cell non-Hodgkin’s lymphoma” (now known as mantle cell lymphoma). It had already progressed to stage 3a, and I was given an average statistical life expectancy of only two and a half years.

Given the short life expectancy I refused the recommended treatment completely.

Click here to read more about Erb Muesli.

Instead, I made radical changes to my lifestyle. As a person who ate a 100 % vegan raw food diet with virtually 100 % compliance for seven years straight and had a very positive experience, I have to be careful not to react cynically.

Yet interested readers may benefit from reading this study if they focus on the details. Incidentally, the Giessener Formel der Vollwert-Ernährungen (Giessener formula for a whole foods diet) recommends eating 50% raw food [Koerber et al. 1994, p. 22]. A 100% raw food diet would certainly be hostile to the industry.

2. Book review

I will start with a description of the study.

2.1. About the study

After a 60-page description of various raw food diet recommendations from the past and present, the author provides a description of the study design, instruments, and methodology. On page 75. there is information about the study groups and their respective diets. On page 100, there is a section with results and a discussion about energy and protein, and on page 158 there are almost eight pages of closing remarks.

The questionnaire that was used takes up 28 pages. The book also includes tables and a 27-page bibliography. On page 197. the author lists 21 diplom theses on the subject of raw food that were published between 1994 and 1998. Based on their first names, I counted only five male authors. Are men that much less interested in the subject of raw food?

2.2. Study design

The study certainly was not an easy task, and Carola Strassner spared no effort.

Definition of raw food in the context of the study: the working group for raw food established the following definition for the study in 1995:

A raw food diet is a diet form that largely or exclusively consists of unheated vegetable-based (and for some people also animal-based) foods. Foods that are processed at high temperatures (e.g., cold-extracted honey and cold-pressed oils) or prepared by heating at low temperatures (e.g., dried fruit, dried meat and fish, and certain types of nuts) are also included. In addition, cold-smoked products (such as meat and fish) and fermented vegetables (using acetic or lactic acid) can be part of a raw food diet [217-14].

Recruiting participants

In December 1992 and January 1993, the team placed recruitment ads in nine popular magazines in Germany. The response rate was 81.7% [217-64], resulting in 1'085 people (in my estimation).

These included the Neuform Kurier (New form courier) (response rate 38.7 %; circulation 1'100'000), Lebenskunde/Fit fürs Leben (Life skills / Fit for life) (response rate 12.4%; circulation 20'000), Schrot und Korn (Groats and grains) (response rate: 11.6%; circulation197'000 ), and Reform Rundschau (Reform review) (circulation: 290'000).

Other magazines accounted for 9.9% of the responses. These included Der Naturarzt (The natural physician) (70'000), Der Vegetarier (The vegetarian) (4'000), Modernes Leben: Natürliches Heilen (Modern life: natural healing) (7'200), Natur und Heilen (Natural healing) (22'500), and Öko-Test (Eco test) (13'500).

Brochures, word of mouth, and the like accounted for the remaining 27.4 % response rate of the total of 1'328 individuals who were sent a pre-questionnaire.


The response rate of 87.6 % should have resulted in 758 questionnaires. I am not clear as to why other participants were excluded because only 572 people received the following psychological questionnaire [Koebnick 1994] and of these only 435 responses were received (76.1 %).

Twenty-four people who were associated with Guy-Claude Burger and inquired about participating in the raw food study were not selected. I could find no explanation as to why, but it became the subject of a diplom thesis [Weiss 1998].

Answers such as I eat a salad every day; I’m a raw foodist, or 8 % of applicants giving merely the parameter that the food they eat is mechanically intact [217-195], was not surprising, especially since advertisements were used as the main form of recruitment. People who provided answers like these were naturally not included in the study.

A comprehensive main questionnaire was then given to all those who in April 1993 reported that they ate a diet of at least 70 % raw food and had done so for at least four months. The final result was 865 participants.

Carola Strassner and her team had valid reasons for not accepting participants under the age of 16. The study also included people who only ate a 70 % raw food diet. This is close to the question: Are they then actually raw foodists?To obtain figures for more stringent criteria, the participants were divided into three groups: those who ate a 70 to 80 %, 80 to 90 %, and more than 90 % raw food diet.

Collage: photography of numerous fruits on market with text inserted on the right.© CC-by-sa 2.0, Collage Catalina Sparleanu, PhD, Foundation Diet and Health Switzerland

Blood samples and measurements

The study leaders invited 343 participants aged 25 to 64 to come and have blood samples and other measurement taken. This was done to accomplish the second objective of the study, which was to assess the nutritional status based on a survey focused on nutritional intake and to evaluate certain parameters in blood samples. The participants who had blood samples taken had eaten at least an 85 % raw food diet for at least 14 months. A total of 236 people came for blood sampling (which was after all 68.8 %).

The seven-day estimation protocol with 236 predefined foods [Bergmann 1994] reduced the number of participants to just 201. These were all nonsmokers who had never had bowel surgery.

The control group and separate dental studies

The real raw food group that consumed more than 90 % raw food in their diet comprised 73.1 %; the next level was 19.9 %. This study was set up similarly to the Giessen whole foods nutritional study (Vollwert-Ernährungs-Studie, VWK) and contains publications by [Groeneveld 1994], [Hoffmann 1994], and [Aalderink et al. 1994] (Aalderink wrote on the motives for health) [217-66].

Women from the Giessen whole foods nutritional study who ate a diet of both cooked and raw foods were used as the control group. Their eating habits as recorded in the nutrition log became the focus of a separate study [Szyperski 1996]. The nutritional intake was determined based on the German Nutrient Database (Bundeslebensmittelschlüssel, BLS) Version II. At the time, this database included more than 11'000 different foods. Using additional data from American, English, Swedish, Danish, and Dutch scientific works, the ingredient information was expanded to include a total of 176 nutrients and ingredients. They only had to make assumptions for a few exotic foods such as the nashi pear (also called Asian pear) and Sharon Fruit (kaki fruit from Israel) [Kroke 1992].

These calculations were made very thoroughly. The study also compared the estimation log of the control group with 72 other participants and with a weight log [Theurer 1996]. BMIs (body mass index) were measured precisely, and using the bioelectrical impedance analysis the proportion of lean and fat mass (divided into body cell mass, BCM, and extracellular mass, ECM) [Straw 1995] was also determined.

Redaction comment

Waist circumference, which is a better indicator of health problems, was not taken into consideration. At the time, it was not yet a standard measurement.

In my opinion, waist circumference should be measured after you have inhaled completely and stuck out your stomach (abdomen). Then measure again after you have exhaled completely and vigorously sucked in your stomach. Visceral fat can’t be displaced as easily as, for example, gasses in your intestines and intestinal contents. The first measurement and the difference between the two would be my parameters.

A detailed analysis of separate dental studies on 129 participants who had a very high proportion of raw food in their diet and mostly consumed fruit was published separately by the team because they suspected that the acidity in fruit attacks the enamel of the teeth [Schlechtriemen 1998].

A joint work by Dr. J. Diehl and Professor M.-L. Moeller (Med. Psych., Univ. Frankfurt) was based on the psychological questionnaire they developed, which 572 participants received. The response rate was 76.1%. The results are found in [Stork 1994], [Wilbert 1995], [Bettinger 1995], [Lehmann 1995], and [Kröner 1995].

The goal was to obtain an overview of any abnormalities in the psychological profile or any health concerns the participants might have. A control group of roughly the same number of people who didn’t follow any one particular type of diet served as a comparison.

2.3. Findings of the study

Of the 201 participants, 53 % were female and 47 % male. Initially, 60 % of the participants were women, who often did not actually follow a “strict” raw food diet. Interestingly, in the 25 to 34-year-old and 35 to 44-year-old groups, there were 23 % more men than women. The two older groups had more women.

Overall, the educational level of the participants is remarkably high, whereby the male participants have a higher level of education than the female participants.

42.8% had earned a university degree, and only 3.5% were unemployed and 4% retired. The monthly per capita income of the participants shows that the majority are among the higher-earning.

78.4 % had been on a raw diet for less than five years. Only five individuals (2.5 %) had been eating a raw food diet for 15 or more years. On average, the study participants had been on a raw food diet for 3.5 years; the longest period was 38 years [217-75ff].

This shows that a large number of the participants were actually just beginning to “get into” raw food and were still experimenting with it.

2.3.1. Protein in your diet

Since protein, or actually the amino acid composition, is considered the most important indicator of a person’s health, the first topic covered is adequate protein intake.

After a brief overview of the types of raw food diets propagated by authors from Ehret, Bircher-Benner, Waerland, Gerson, Sommer, Kollath, Evers, Bruker, and Schnitzer to Wandmaker, Burger and other German and foreign raw food authors, readers are provided with a wealth of information (and also a lack of information) about current findings on protein.

Collage of own photos of 5 dishes with raw natural food with explanatory text.© CC-by-sa 2.0, Collage Catalina Sparleanu, PhD, Foundation Diet and Health Switzerland

Some of these nuts and seeds contain a lot of protein, while others have different benefits, for example, flaxseed is the world's best source of omega-3 fatty acids.

In actual fact, science knows far too little about proteins. These high molecular weight condensates of amino acids, with more than 50% dry matter, are involved in building tissue and in the processes of active ingredients (enzymes and hormones).

Most of the 20 amino acids (there are more than 100 in nature) that the human body needs as building blocks for proteins are produced by the body itself. Some of these are essential (essential amino acids).

The essential amino acids considered to be possibly lacking in a vegetarian / vegan diet

However, science is not certain as to which amino acids are really essential amino acids, meaning they cannot be made by the body and must be consumed in food. Recent studies show that intestinal bacteria contribute as well.

The essential amino acids that are considered to be possibly lacking in a vegetarian diet include only leucine, lysine, and threonine and in a vegan diet also methionine and cysteine as long as the caloric values are within the correct levels. Children also need arginine.

Grains are the main source of protein for humans worldwide [Young and Pellett 1985]. In developing countries, plant-based foods are the primary source of dietary protein and often the only source [Bodwell 1979].

Apart from animal-based products that are rich in protein, other foods such as algae (e.g., chlorella, and spirulina), yeasts, and protozoa also contain a lot of protein [Belitz 1993b].

Nitrogen content is considered the yardstick for protein. Milk contains 17%, but nuts, for example, provide 19%.

Heating foods denatures proteins and causes a partial or complete loss of enzymatic activity or changes in functional behavior [217-18].

Fruits and vegetables are often blanched prior to freezing in order to inactivate enzymes such as lipases, lipoxygenases, proteases (peptidase), polyphenol oxidases, and glycohydrolases so that the taste, color, and texture don’t change.

On that note: A number of enzymes in foods are toxic or can produce toxic products if they stay active [Andrews in 1993].

Lysine, in particular, is lost at a rapid rate as a result of the Maillard reaction with carbohydrates.

The Maillard reaction

The author discusses the Maillard reaction by beginning with the following commnet: The result is a loss of sugars and amino acids, the formation of harmful substances that are anti-nutritive or toxic, and appetizing aromas. Dairy products that contain a large amount of lactose and thermolabile proteins are particularly sensitive, she adds and also calls attention to the mutagenicity (mutagen) of Maillard molecules [217-20].

In addition, the author states, Under severe heat, dietary protein may become resistant to digestion ... When protein-rich foods are cooked, heterocyclic amines form, which were shown to be carcinogenic in vitro mutagen and animals ... In one study, fruits and vegetables were found to be strong factors active in the inhibition of mutagenic pyrolysis products of amino acids in 11 of 59 tested food groups [Morita et al., 1979].

Raw foodists are often interested in issues such as the following, which I address in another article:

There are still large gaps in knowledge about the health benefits/implications of the many compounds found in natural, cooked, and processed foods [Gray and Morfton 1981]. The thousands of naturally occurring mutagenic substances in vegetables, fruits, spices, and the like are often not given sufficient attention. The same is the case with carcinogenic and cancer-inhibiting substances [Jallut 1989].

According to [Mauron 1985], it is best to minimize such products in your diet. Mauron is obviously referring to the products that have predominantly negative effects [217-21].

2.3.2. Our protein and energy requirements

Recommendations concerning protein and energy have changed greatly and also multiple times in recent decades. This is because earlier recommendations were based on assertions that “good protein” is only found in animal products.

No understanding of the fact that humans can get enough protein without eating animal products

This is why we find long quotations such as the following which show no understanding of the fact that humans can get enough protein without eating animal products [217-22].

Although the German Nutrition Society, along with the Scientific Committee on Food (SCF), uses the guidelines provided by the FAO/WHO/UNU of 0.75 g/kg/d, it believes a further increase of 0.05 g/kg/d would be appropriate as the digestibility of the reference protein is between 90 to 95% [Nutritional Requirements Committee, German Nutrition Society, 1995a, 1995b]. [UNU stands for United Nations University].

In Europe alone, there are a number of different recommendations for protein intake. For example, France recommends 81 g/d for adult men, the Netherlands recommends 70 g/d, and Spain recommends 54 g/d [Bender 1993a].

The SCF, which is part of the Commission of the European Communities [CEC 1993 p. 1f]) distinguishes between three recommendations as follows. The Lowest Threshold Intake (LTI) amounts to 0.45 g protein/kg of body weight; under this level it is likely that the majority of individuals would not be able to maintain their metabolic integrity.

The Average Mean Population Requirement (AR) is the average for normal distribution of the protein recommendations; this is 0.60 g protein/kg of body weight. The recommendation that would cover the needs of nearly all healthy people in a group is the Population Reference Intake. This recommendation is 0.75 g protein/kg of body weight.

These recommendations are made under the assumption that the requirements for energy and all other nutrients are met.

For some time now, studies have shown that we can be healthy eating a pure plant-based diet. Entire populations that have eaten a strict vegetarian diet for numerous generations are also proof of this. Just think of Jainism, a religion that has existed for more than two and a half thousand years.

Nevertheless, it wasn’t until about 1996 that the scientific community finally recognized this fact — although the majority of individuals still didn’t accept it. This is natural. It is very rare that a professor would recant and adopt a new view. In this case, attack is the best defense.

Protein intake is very controversial

Healthy adults can get the protein they need from plant sources alone [1990 Menden pp.14f, ADA 1980, Barness 1977].

Protein intake is very controversial: In a 1991 FAO report, it was decided in regard to protein quality that the values for the amino acids requirement from the 1985 report [FAO/WHO/UNU 1985], (based on experiments conducted by [Rose et al.]) would no longer be accepted or considered nutritionally relevant because there had been a number of recognized methodological errors.

The MIT values are again only provisionally valid since according to the IDECG (International Dietary Energy Consultancy Group [Clugston et al., 1996], Young and Scrimshaw are planning to conduct a full meta-analysis of the available data.

It is important to understand that with only a few exceptions almost all dietary proteins are made up of all 20 amino acids, but that these are found in different compositions [Bender 1993b]. It is also important to know that the experimental and biochemical basis of protein requirement values is less well-founded than assumed.

The highly praised combination of an egg and a kilogram of potatoes is no longer valid either. In one study, wheat or rather gluten protein was limited to less than 0.2 g/kg of body weight. The protein consumed was apparently fully metabolized regardless of what type of protein it was, and the biological value of the protein was estimated to be 100 or higher [217-30].

The order in which the essential amino acids are limited seems to depend partly on the amount of total nitrogen supply[Scrimshaw and Young 1978].

A raw food desert from "The Raw Gourmet" by Nomi Shannon. Photo: Edmond Fong.© CC-by-sa 2.0, Edmond Fong / Nomi Shannon

A protein and vitamin-rich raw dessert.

Such a treat should be the exception, but I highly recommend these natural, unprocessed ingredients (e.g., nuts and almonds).

Nuts can help you regulate your weight and almonds, in particular, are important to eat on a daily basis as they contain iron and various B vitamins.

The main ingredient in this dessert called “Very Carrot Cake” is the carrot pulp, which was left over after making carrot juice.

I have named the following three subtitles to show how false scientific findings can cause harm and misunderstanding for decades. With the exception of my comments, the information in these sections comes from the book.

2.3.3. The myths about plant protein

When you explain what a person on a strict raw food diet (perhaps even vegan) eats, people always have doubts as to whether such a diet is even possible at all — and physicians are no exception.

But there are many dangers that you must watch out for as another chapter of my paper shows. However, the “myths” about not being able to get enough protein if you eat “only” plant protein were disproved by Young and Pellet [Young and Pellet 1994].

Myths Today, we know that the following is true:
Plant protein is not a complete protein; it lacks specific amino acids. Plant protein is a complete protein, but specific types of plant protein can have low levels of certain amino acids.
Plant protein is not as ’good’ as animal protein. The quality depends on the source and dietary composition of the plant protein. It can be equivalent to high-quality animal protein.
Protein from different plant-based foods must be consumed simultaneously during a meal in order to achieve a high nutritional value. Different sources of plant protein do not have to be consumed together; it is more important to keep a good balance throughout the day.

I don’t want to quote all of the myths, but only want to point out that the myth that plant-based protein is more difficult to digest is obsolete as is the myth that eating only plant-based protein is not adequate. My comment: A vegan diet is now considered to be a good option ... (p. 31)

Nitrogen balance

[Crim and Munro 1994] state that when protein intake is low, the improvement of the nitrogen balance is proportional to the amount of additional protein. But when protein intake increases, metabolism becomes less efficient.

About 1 to 1.5 hours after oral administration, marked proteins can be detected as amino acids in serum.

The labile protein pool is sufficient for almost an entire day, and available protein can be used for another 6 to 8 weeks before loss of functional tissue takes place [Gassmann and Kübler 1994].

Experiments suggest that 250 to 300 grams of protein are synthesized daily by the adult body. Approximately 70 g of protein are secreted daily in the intestinal lumen.

In addition, a large number of amino acids are recycled as part of protein metabolism. Even with an intake of less than 30 cal/kg and nitrogen consumption below 50 mg/kg, both are efficient enough to improve the nitrogen balance [217-40].

Something that few people know: Normally one-third of the urea produced travels to the intestines and can be hydrolyzed by intestinal bacteria. This makes urea-nitrogen available for metabolic interactions, but the necessary carbon skeletons can be a limiting factor.

Another thesis not yet definitively proven is that the bacteria in the intestines fix nitrogen [Koishi, 1990, Tanaka et al., 1980].

According to [Düro and Schnur 1989], 5 g of nitrogen per day results in a good nitrogen balance in adults, and the intake of carbohydrates improves protein utilization. If food intake is reduced, the body reduces the excretion of urea.

According to [Acosta 1988], diets high in fiber are more likely to result in weight loss in obese men than are diets that restrict calories.

2.3.4. Too much animal protein

If you think that a raw food diet has to be a vegan or vegetarian diet, you are mistaken.
All edible raw foods qualify as raw food. Whether foods are not processed or undergo minimal or intensive processing is yet another topic. In general, I have not eaten meat since 1978, but every now and again I do have some sashimi.

Plate of sashimi: raw fish and raw vegetables. Tuna, Cuttlefish and Seabream.© CC-by-sa 3.0, Suguri_F, Wikipedia
Sashimi is raw fish and raw vegetables prepared in a Japanese style. My wife and I always look forward to this dish as it is a delicacy that we only eat on the rare occasion. Apart from this, we prefer not to eat any animal products as we have environmental concerns.

In Western countries, at 90 g/day the average protein intake is significantly higher than the recommended value. This causes excessive production of urea and abnormally high renal function. And it can also lead to increased kidney weight and renal impairment [Menden 1983].

Osteoporosis, cardiovascular diseases, gout, certains forms of cancer and stroke

A higher protein intake causes more calcium to be excreted in the urine, which promotes osteoporosis [Anon 1981]. But if your phosphorus intake is also higher than normal, this effect is lessened.

Consuming a large amount of animal protein is more likely to lead to cardiovascular diseases [Leitzmann and Hahn 1996a p.103] and promote high blood pressure (also called arterial hypertension) — both of which can have severe consequences.

The study [Gelfand and Sherwin 1986] indicates that fructose has little direct impact on "insulinsecretion", but that it has a noticeable protein-sparing action. It is a known fact that consuming high levels of animal protein increases the risk of gout, but fewer people know that there is also a strong correlation between the consumption of animal protein and specific cancers such as colon and breast cancer, and possibly pancreatic and prostate cancer [National Research Council in 1990 S.259f] [217-46].

It is undisputed that excessive consumption of animal protein over a long period of time increases the risk of strokes. According to [Flanigan et al., 1995], consuming less dietary protein and according to [Barsotti et al., 1991a, 1991b, 1990], eating a vegan diet decreases uraemic symptoms.

2.3.5. And the opposite?

On malnutrition: A longer period of malnutrition associated with weight loss in normal test subjects causes increased fatigue, muscular weakness, and decreased motor activity. In contrast, patients with anorexia nervosa (anorexia) show more activity up to excessive activity although they have a reduced energy supply.

Protein-energy malnutrition (PEM), also known as kwashiorkor or marasmus, is often accompanied by infections and a lack of vitamins, minerals, and/or trace elements. When sodium levels are elevated, deficiencies in potassium, magnesium, and vitamin A occur, and the immune system is compromised. [217-48].

Protein-energy malnutrition and chronic energy deficiency

In kwashiorkor (probably potassium deficiency [Golden et al., 1982a]) the most important characteristic is edema, whereas in marasmus it is muscle atrophy and loss of subcutaneous tissue.

CED stands for chronic energy deficiency and is the most widespread type of malnutrition. Three decades of research on the effects of CED in connection with behavioral development have brought no conclusive results [Pollitt]. For growing children, medicine distinguishes between two distinct reactions in malnourishment:

  • Type I nutrients are minerals and vitamins that are responsible for specific functions and produce specific nutritional deficiencies; the diagnosis is clear.
  • Type II nutrients are electrolytes and other minerals (potassium, sodium, magnesium, zinc, and phosphorus) as well as protein and energy that result in no characteristic signs or symptoms when lacking.

2.4. Food intake

In the test group, 27.3 % were vegan raw foodists who ate a diet free of any animal-based foods (apart from honey). Vegetarians (lacto-vegetarians, ovo-vegetarians, and lacto-ovo vegetarians) made up 44.8 % of the test group, and omnivore raw foodists, who also ate meat and/or fish accounted for 27.9 %. Consumption of fish and seafood was almost entirely in raw form, and for the women of the group it was actually 100 % in raw form [217-83].

Variations in the diet type and the proportion or raw food

After all, 73.1 % of the participants ate an almost pure raw food diet (at least 90 %), and the next group (19.9 %) ate more than 80 % of their food raw. The group of those who ate 90 to 99.9 % raw foods included 81.9 % men and only 65.4 % women.

It is striking that 35.1 % of the men and only 20.6 % of the women adhered to a strict vegan diet. However, in contrast, 30.9 % of the men were omnivores (eating animals and plants), but only 25.2 % of the women were in this group. Variations in the diet type and the proportion or raw food taken together show an even wider range of differences [217-77ff].

With regard to their professional career, more of the female raw foodists are fully employed than the female vegetarians or omnivores.

When compared with either women who ate whole foods or female omnivores, women on a raw food diet did not exercise more.

They are far behind on average (about one-third) but achieve more than double the results if they are very active in sports. With male raw foodists, 20.9 % rarely or never exercise, but 52.3 % exercise a lot.

A weak point for the raw foodists group is certainly the high percentage of people who don’t exercise at all.

Only 6.5 % of the women on a raw food diet took sex hormones as compared with 16.9 % of the vegetarians and 38.3 % of the omnivores [217-81]. According to the main questionnaire, 68.7 % of the raw foodists did not take any medications or supplements.

Conventional medicine and the pharma industry make people believe that their special diet is deficient

My comment: It’s a shame that medications and supplements were put into the same category as these are taken for two very different reasons.

Conventional medicine and the pharma industry make people believe that their special diet is deficient, and this may be why many raw foodists take supplements — just to be on the safe side. This is in spite of the fact that raw foodists automatically get more of the most advertised vitamins, such as vitamin C, in their diet than people on a “normal” diet or omnivores.

At least the traditional school of thought believes that raw food leads to anemia ...

The participants’ alcohol consumption was quite low. More than half (58.2 %) didn’t drink any alcohol at all, 38.3 % drank up to 15 g of alcohol per day, and only 3.5 % drank more. In contrast, 85 % of the omnivores drank some alcohol every day.

There was an extremely low proportion of smokers in this group of raw foodists. The average raw foodist in the study consumed 2,050 g of plant-based foods and 50 g of animal-based foods on a daily basis.

Animal-based foods, milk, grains, fluids and fruits

In the group of omnivores, the proportion of animal-based foods was higher at 4 %, or about 80 g per day, while for vegans it was 0 %. Overall, the animal-based products can be broken down into 55 % (28 g) milk and dairy products, 20 % meat and meat products, 18 % fish and seafood, 6 % eggs (approximately half an egg a week, preferably raw), and surely about 1 % honey.

The participants preffered to drink milk, about 5.5 g per day, as raw milk. The people examined as part of this study ate an average of 1'423 g of fruit, 489 g of vegetables, and 48 g of nuts and seeds, which adds up to 1'960 g. In addition, they consumed 7.6 g of cooking oils and 15 g of potatoes, of which 3.2 g were raw.

Specially prepared foods using recipes from raw food books, for example, by Ann Wigmore made up only about 6.4 g of daily consumption. Grains and processed foods comprised an average of 29 g, bread and baked goods added up to 19 g [217-87]. Soy products accounted for 3 g (also heated) and sweets and desserts came up to 6.7 g. The remaining 3.3 % of the 2'050 g fell into the miscellaneous category.

The vegetarian and vegan raw foodists ate a diet of 98 % raw foods, and at 13 mL the vegan raw foodists also had the lowest alcohol consumption.

The fact that the vegetarian raw foodists ate even fewer nuts and seeds than the “omnivores” (40 g) is actually surprising and does not say much about their knowledge of nutrition and dietary needs.

The female participants consumed 1'065 mL of fluids per day, whereas the male participants were only at 834 mL per day. Both groups easily met the fluid intake of 2.1 liters recommended by the German Nutrition Society (Deutsche Gesellschaft für Ernährung, DGE), but in a different way because 200 mg of electrolyzed water (from burning essential nutrients) plus the water intake from the plant-based foods were also available to the body. As a result, the total amount of liquids came to 2'536 mL since an average of 1'615 mL came from solid foods.

The following statement is found in the study: Overall, they seem to achieve the overall recommendation even without the electrolyzed water as they consume a large amount of water-containing foods [217–87]. And before that: This doesn’t seem to be a problem for the participants in the raw food study since they primarily eat water-containing foods.

The fact that the raw foodists consumed nine times less bread and baked goods as well as less milk and dairy products and significantly fewer sweets than those who ate whole foods or a “normal” diet was to be expected.

Consumption of meat and meat products was only 10 % of that what people on a “normal” diet ate. About half of the subjects refrained from eating grains completely.

Since fruits comprised the highest proportion, this category was divided into six groups: berries (63 g), drupes or stone fruits (14 g), pome fruits (331 g), wild fruits (0.1 g), citrus fruits (341 g), and tropical fruits (587 g not including citrus).

The consumption of wild fruits was quite insignificant, whereas tropical fruits were eaten in the greatest quantities, followed by citrus fruits and pome fruits. It is not surprising that apples (267 g), oranges (263 g), and bananas (228 g) were the fruits most commonly consumed.

This is followed by avocados with 90 g, pears at 63 g, pineapple at 54 g, and grapes at 50 g. Dried fruit comprised only 88 g despite the fact that the survey was conducted at a time of year when fewer fresh fruits were available. Of this, tropical fruits had the lion’s share with 76 g. Dried dates were listed separately at 49 g.

Several other individual fruits were worth mentioning as they accounted for at least 45 grams per day. These included cherimoyas, grapefruit, honey melons, persimmons, kiwis, tangerines, mangos, and papayas. Sharon fruits, watermelons, and dried figs came to more than 10 g.

But we can expect these values to change in the summer when more local and inexpensive fruits are available — there is simply less fruit offered between the months of February and April when many varieties are out of season.

Book cover "Rohkost - schmackhafte Gerichte für die gesunde Ernährung".© CC-by-sa 2.0, Foto Ernst Erb, Foundation Diet Health
This was most likely my second raw food recipe book from 1978. At least beginning in 1980 when I lived in Tenerife, I used the fruits and vegetables grown in my own garden. I prepared them quite simply by washing them briefly and sometimes chopping or slicing them before eating.

Kitchen work wasn’t necessary. If anything, I had to do some work with my bees.

There are very good vintage bookstores, thrift stores, and the like. You can often get raw food books like this for no more than a dollar, and they are still highly relevant today.

2.4.1. Nutrient intake

Conclusion: According to the exaggerated values set by the German Nutrition Society, vegans with a high proportion of raw food in their diet would achieve all of the recommended values except for the following: vitamins D, B2,and B12, as well as the minerals calcium, zinc, and iodine.

The overall nutrient intake

The overall nutrient intake was as follows: the men consumed 287 g of carbohydrates, 67 g of fat, and 46 g of protein, and the women consumed 238 g of carbohydrates, 59 g of fat, and 39 g of protein.

Fiber intake was 65 g for men and 55 g for women, cholesterol 24 mg versus 29, linoleic acid 16 g versus 14 g, saturated fatty acids 11 g, monounsaturated fats 28 g versus 24 g, polyunsaturated 17 g versus 14 g, and purines 200 g versus 191 g.

Vitamin A intake was 2.4 mg RE/d (100,000 IU = 30 mg RE, RE = retinol equivalent), retinol for men 32 µg, for women 50 µg (both zero), beta-carotene 14 mg (11 mg), vitamin D 3.2 µg, vitamin E 19 mg, vitamin K 637 µg (540 µg), B1 1.7 mg, B2 1.5 mg, B6 3.5 (2.7 mg), and B12 0.3 µg (down to zero).

The total intake of folic acid (477 µg, 458 for vegans) was 514 µg for men and 449 for women. Niacin intake was 477 mg, biotin 62 µg (58 µg, but 68 µg with a 90% raw food diet), and vitamin C more than 430 mg.

Sodium 729 mg (401 mg), potassium 5,953 mg, magnesium 596 mg (645 male versus 562 female), calcium 841 versus 686 mg, phosphorus 1,408 mg (1,231 mg), iron 20 mg versus 18 mg (18 mg), zinc 8.8 mg (8.1 mg), and iodine 113 µg (94 µg).

Redaction comment

For the purely vegan raw food group, I only added the values in parentheses if they were significantly below the average listed. The other groups have correlated increased values.

If we disregard the most commonly discussed issue of protein, conventional science refers to these as the critical substances in nutrient intake. This is not usually a problem if vegan raw foodists make sure they have a varied diet and maintain a balanced calorie intake. In the ideal case, we should aim for our ideal biological weight which is 10 % below our normal weight. This can easily be achieved by eating nuts and seeds.

Here are some examples of possibilities for a cumulative report and a few comments.

Vitamin D

Vitamin D (only necessary in the case of low sun exposure, high reserves)

People who get enough exposure to the sun produce their own vitamin D in sufficient quantity — and this then lasts for 20 days. If this is the case, you don’t need to take vitamin D supplements; otherwise, the German Nutrition Society recommends 5 µg.

The study compares the raw foodists with studies of children on a macrobiotic diet and similarly low levels of vitamin D intake and a prevalence of 55 % rickets in winter.

As of 2013 there was not yet scientific consensus regarding vitamin D. Wikipedia includes the following on the subject:

A 2013 review did not find any effect from supplementation on the rates of disease, other than a tentative decrease in mortality in the old. ... Low vitamin D levels may result from disease rather than cause disease. ... Vitamin D2, alfacalcidol, and "calcitri.." do not appear to have any beneficial effects with regards to the risk of death. However, both an excess and a deficiency in vitamin D appear to cause abnormal functioning and premature aging.

I discuss how you can avoid this problem while remaining on a raw food diet in another article. Our recipe and ingredients program also lists this vitamin, even though many standard tables often don’t include it.

Mushrooms, for example, have 2 to 3 µg per 100 g of vitamin D, but it is in the form of ergosterol, and the body needs sun to convert it. For this reason, there are irradiated mushrooms (agaricus bisporus) available for raw consumption (at least in the US) that contain 11 µg/100 g of vitamin D.

Alfalfa is another plant-based source. See also Wikipedia on "ergocalcifer..". The Wikipedia entry on alfalfa also lists out the vitamin content of the mainly forgotten lichens.

Raw herring contains 31 µg/100 g. But other types of fish, such as halibut or tuna, contain only about 5 µg.

Vitamin B2, Riboflavin

Vitamin B2, Riboflavin (DGE 1,7 mg)

With just a few more almonds a day, even the risk group can meet the vitamin B2 recommendations made by the German Nutrition Society.

Almonds contain between 0.6 to 0.92 g/100 g of vitamin B2.

Even a few grams of brewer’s yeast or other dry yeast are enough to ensure you are getting enough vitamin B2 (4.5 g/100 g).

Broccoli should not be disregarded either as it contains 0.2 mg (comparison: breast milk (0.04 mg)).

Even raw mushrooms contain 0.45 mg.

Vitamin B12

Vitamin B12 (German Nutrition Society recommends 3.0 µg, but the FAO and WHO only recommend 1.0 µg)

The German Nutrition Society recommends an intake of 3 µg, but the FAO and WHO recommend only 2 µg (with an anticipated resorption of 50%).

The body stores it for years and adapts the absorption capacity and consumption to its reserves. More on this topic later as it is quite complicated.

Some people believe that a few grams of yeast a day is enough to cover vitamin B12 needs. And some people like dried brewer's yeast sprinkled on salad or an avocado. However, older people, vegetarians, and vegans often develop a vitamin B12 deficiency, which happens gradually over several years.

In contrast, people with certain operations (ileum) or defects (e.g., intrinsic factor, IF reduced or absent) often develop health problems quite quickly, although these don’t always show up right away.

A separate article covers this.


Calcium (German Nutrition Society recommends 850 mg)

The amount of calcium recommended by the German Nutrition Society and also the FNB (Food and Nutrition Board) in the United States is only required for people who consume a lot of protein. The milk problem comes into play here, a topic I discuss in several other articles.

Nevertheless, almonds contain 252 mg per 100 g, dried figs 190, hazelnuts 225, dried dates 61, broccoli 113, endive 68, fennel 109, and cabbage the high value of 230 mg. It would have been very helpful for consumers if recommendations like these were included in the book.


Zinc (German Nutrition Society recommends 12 mg)

Zinc deficiency should not be a problem if you eat a varied diet. For example, pine nuts contain 14 mg, almonds 3.1, hazelnuts 2.4, Brazil nuts 4.2, pecans 4.5, walnuts 3.0, broccoli 0.9 , peas 1.6, and carrots 0.52 mg.


Iodine (German Nutrition Society recommends 190 µg, FNB 50 to 100)

Carola Strassner herself noted the following: However, the data concerning the iodine content of food is still surrounded by uncertainty.

The German Nutrition Society must be calculating in a very large safety margin for the mountain areas that have a very low iodine supply, in order to make consumers aware of the problem.

According to [FNB, 73], an intake of just 50 to 100 µg a day would certainly prevent goiter. Other sources recommend 44–162 or 100–200 µg.

Iodine content varies depending on the chemical composition of the soil (erosion by glaciers).

Lamb’s lettuce contains up 62 µg, broccoli and carrots each 15, and pineapple 10 — pollack contains 200 µg and cod liver oil contains 510–870 µg/100g.

However, it is very easy to get the “safe amount” even on a 100 % vegan raw food diet.

Cover of "Raw Food Made Easy" by Jennifer Cronbleet, 2005.© CC-by-sa 2.0, Foto Ernst Erb, Foundation Diet Health
In the United States, a country of great contrasts, there is a particularly wide selection of raw food books, and also raw food restaurants, some of which are even vegan raw food restaurants. You can find these even in small towns like Durango, Colorado. The raw food restaurants in New York City or other large cities, however, offer sophisticated gourmet raw food dishes.

I haven’t found as many in Europe. But I would love to make a list of raw food restaurants here. If you know of any, please send me the name and relevant information. You can use the form provided at the end of this article. Thank you.

2.5. Energy balance, body weight, and the like

The study shows an average daily energy intake of 1'976 cal or 8.3 MJ per day, for men specifically 9.0 MJ (megajoules) and for women 7.4 MJ. The vegan raw foodists got up to an average of 7.9 MJ. This means that 57 % of participants did not achieve the values recommended by the German Nutrition Society of 10 MJ for men and 9 MJ for women.

However, the author goes on to say: A group of five rheumatic patients who ate a vegan diet for three months had a dietary energy intake of 8.0 plus/minus 1.7 MJ per day, which was significantly higher (p > 0.001) than with their normal diet.

... Another group of subjects who followed the Living Food Diet for either a week or a month had a higher average dietary energy supply (8.0 MJ/d) than the control group (7.7 MJ/d) that had followed a normal Western mixed diet [Hänninen et al., 1992, Peltonen et al., 1992].

Vegetarian or vegan raw foodists and vegans do not always achieve the recommendations

Studies from numerous countries (including the Seventh-Day Adventist Church in Canada and the United States) show that vegetarian or vegan raw foodists and vegans do not always achieve the recommendations. An example is a study that examined the diet of Seventh-Day Adventists, where the women consumed 1'600 cal and the men who did more physical labor consumed 2'400 cal.

Redaction comment

The study also compared these values with developing countries such as Sierra Leone and Ecuador [Young and Pellett 1990]. A proper balance is achieved when a person neither loses nor gains weight. However, there is no discussion of the fact that the basal metabolic rate (e.g., brain, heart, and digestion) common for people on a vegan raw food diet lowers cardiac and digestive capacity dramatically.

A person usually reaches their ideal biological weight within six months of beginning a vegan raw food diet. There is only some speculation about the topic on page 163.

According to statistics [29–129], the ideal biological weight is generally 10 % below the Broca ideal weight and 20 % below the Broca normal weight (see above).

Reason for the reduction of the basal metabolic rate in relation to the heart and digestion is that vegan raw foodists achieve very low blood pressure and a resting heart rate of 38 to 50 beats. Digestion is completed within 24 hours, rather than taking several days.

The heart will beat only a limited number of times. Go ahead and calculate how advantageous a low resting heart rate — without pathological bradycardi or athletic heart syndrome — or low blood pressure at full physical fitness would be. Science does not yet recognize that this can be achieved not only by healthy exercise, but also by a vegan raw food diet.

A study conducted by [Shimazono 1990] shows the effects of the introduction of the Western diet in Japan:

Before and immediately after the Second World War in Japan, the ratio of vegetable to animal foods was 1:20, with mostly fish and mussels making up the majority of the animal-based foods. That adds up to just 5 % animal-based foods. Milk and dairy products were practically nonexistent.

Today, the ratio is 1:1 [217-110], and lifestyle diseases and obesity are now very common in Japan.

At least the author came to the following conclusion through an enumeration and rough comparison of the many different diets, for example, the Lifestyle Heart Study:

It is remarkable that out of all the various (alternative) types of diet, the recommended nutrient intake is most often achieved with a raw food diet [217-112].

Body weight

The male participants in the study weighed an average of 150 lbs plus/minus 20 lbs (68 kg, plus/minus 9 kg), and the female participants about 124 lbs plus/minus 17.5 lbs (56 plus/minus 89).

The vegan raw foodists weighed an average of 132 lbs plus/minus 22 lbs (60 kg plus/minus 10 kg). Men lost an average of 28.5 lbs and women 22 lbs (13 kg and 10 kg). This can be read from the highest and lowest weights in the statistics.

A total of 87% of the men and 71% of the women were satisfied with their body weight. Interestingly, where participants were not happy with their weight, the men more likely wanted to gain weight and the women wanted to lose weight.

Redaction comment

Note from me: Body mass index (BMI) is now more commonly used than the Broca’s index with the comparison of kg or pounds to height (1 meter or 3.3 feet and taller) because the BMI correlates relatively closely with the percentage of body fat and doesn’t yield false results, particularly for shorter or taller people.

To get the Broca normal weight in kg, you would subtract 100 from your height in cm minus a deduction of 5 % for women. For the Broca ideal weight, you would instead subtract 10 %, and for the “ideal biological weight” you would subtract an additional 10 % on top of the first 10 % [29].

BMI is your weight (in kilograms) divided by your height squared (in meters). Example: Height: 1.77 m × 1.77 m = 3.1329 at a weight of 63.3 kg would result in an index of 20.2. An index of up to 20 (women up to 18.5) is considered “underweight.”

However, the “ideal biological weight” calculated according to [29] with the Broca formula would be 77 minus 10 % = 69.3 minus 10 % = 63.3 kg, which in turn corresponds to a BMI of 20.2. The upper limit of “underweight” therefore corresponds to the ideal weight.

A normal weight or BMI is currently considered to be 20–25 (19–24 for women). With a BMI of 25 (24) to 30, a person is considered overweight and above that obese.

Studies involving people with high blood pressure (essential hypertension) clearly show how eating a raw food diet results in important and significant weight loss. Diets high in fiber are more likely to bring about weight loss in obese men than are calorie-restricted diets [Acosta 1988].

An important finding: None of the raw food groups have body weights so low as to be comparable to people who have anorexia nervosa.


Men on the raw food diet were not afflicted with obesity. There were only 0.9 % women who had a BMI in the obesity bracket. For people on a whole foods diet, the obesity rate was 1.2 % and for those on a “normal” diet, 11.5 % women were obese.

The one obese person most certainly must not have been on a raw food diet for long because she was part of the extreme raw food group. A total of 19.1 % of the men and 8.4 % of the women on the raw food diet were overweight. On the whole foods diet, 18.2 % of the women were overweight, and on the “normal” diet 37.9 % of women were overweight. This means, at least for these men, that they began a raw food diet in order to deal with obesity.

A total of 10.6 % of the male raw foodists and 25.2 % of the female raw foodists fell into the underweight category. In comparison, 14 % of the women on the whole foods diet, and 5.7 % of the women on a “normal” diet were classified as underweight. Vegan raw foodists are underweight more often than are omnivores.

A group of women who had been on the vegan Living Food Diet for 0.7 to 14 years had an average BMI of 21 plus/minus 3 kg/m2 [Rauma et al., 1995b].

Redaction comment

It should be noted that this is pretty much equivalent to the ideal biological weight although it is, of course, significantly lower than in the control group. In "Die Cholesterin-Neurose" (The cholesterol neurosis), Hermann Mohler discusses weight in relation to life expectancy and provides a graph on page 129.

People who are 10 % below the “normal weight” have the highest life expectancy; those with a normal weight have only a slightly lower life expectancy.

A group of women who had been on the vegan Living Food Diet for 0.7 to 14 years had an average BMI of 21 plus/minus 3 kg/m2 [Rauma et al., 1995b].

In terms of body composition, (in other words the ratio of extracellular mass (ECM) to body cell mass without fat mass (BCM)), lean body mass is relatively high because 44.9 % have an ECM/BCM ratio of below 1.0.

The total body water and the basal metabolic rate

The total body water of those in the raw food group is closer to the upper limit of the normal range, and 31.8 % are above the normal range. In terms of the percentage of lean mass, they are rather high (raw foodists total 77 % with a standard range of 70 to 78 %). From the overall group, 84.8 % were in the normal range for the phase angle.

The phase angle, which is mostly in the normal range for the entire group, indicates preserved membrane integrity. This tendency should be regarded as important as a reduction in the BCM (if at all) is much slower than the body’s compensation for a reduction in body fat. A BCM decrease with a simultaneous increase of the extracellular space is characteristic in the early stages of malnutrition [217-122].

The majority of participants (66.2 %) were in the normal range of the meta-index, and only 3.5 % were below this range.

The majority was also in the normal range for the Kappa index as well; only 9.1% was above the range.

Unlike body fat percentage (BF), for which the raw food diet participants were in the normal range, workers in India were at 6.1 %, and a control group was recorded to have 14.3 % body fat.

But: An increasing ECM/BCM index calls attention (at an early phase) to deterioration of the nutritional condition. ... The LBM of raw foodists as a whole is relatively high (p.124) (LBM stands for “lean body mass”).

See also bioelectrical impedance analysis (BIA).

The basal metabolic rate of vegan raw foodists is in general lower than for other people, and the study therefore concludes: In chronically undernourished people, it is possible that a lower basal metabolic rate per kg of body weight is attributable to changes in body composition, more precisely to a reduction in muscle tissue and an increase in the nonmuscular part [Shetty et al., 1996].

This cannot be ruled out for raw foodists either. Since the energy requirements and other requirements depend on body weight, lower energy consumption could still be sufficient [217-127].

The median protein intake of the participants was a total of 41 g (46 g for men, 39 g for women). Only 27 % of the vegetarians and vegan raw foodists reached the values set by the German Nutrition Society, which are clearly “industry-friendly” and too high. See more recent literature such as the China Study. You can also find the book review here. The nutrient density of protein was 5.4 g/MJ for the whole group.

But all groups reached the AR (average mean population requirement) of the Commission of the European Communities, Brussels (CEC) of 0.60 g protein/kg of body weight(!).

Protein intake

If the quantities are based on body weight, vegetarians and vegans are quite capable of achieving the recommendations [Carlson et al., 1985, Abdulla et al., 1984].

A study conducted by [Agarwal et al., 1984] clearly illustrates that the daily intake of 0.53 g/kg of vegetable protein (grains, legumes, and vegetables) is sufficient for healthy active women. It was not discussed to what extent an adaptation of the metabolism of these Indian women played a role.

As a comparison: In Japan, 53 g of protein was the average intake shortly before the Second World War. In 1945, it had fallen to about 36 g/d. But today, the average person in Japan now consumes about 78.9 g/d of protein a day (reference year 1986).

And in the United States, the average person now consumes 100 g of protein per day! The raw food diet participants consumed almost 50% of their protein intake from fruits and vegetables.

The vegan raw foodists consumed 39.4% from fruits, 21.4% from vegetables, 12.4% from nuts, 16.1% from seeds, 5.6% from grains, 2.3% from drinks, and 2.8% from “other miscellaneous” sources.

Cover of "Exotische Früchte und Gemüse - kennen, zubereiten, geniessen" by Brigitte Kranz© CC-by-sa 2.0, Foto Ernst Erb, Foundation Diet Health

I already had this cookbook when I lived in Tenerife (1980s). This is not a purely raw food cookbook, but contains a number of raw food recipes.

In other words, the cover photo is deceptive (even if this is not intentional).

I would very much welcome it if you would like to submit a short book review on a raw food cookbook. The selection of used books on the subject of raw food is quite large.

I am particularly interested in books that do not recommend a specific direction. In my mind, these are “factual raw food books” as opposed to sectarian or even esoteric books. The latter often provide advice that doesn’t promote a balanced raw food diet.

Essential amino acids

Concerning essential amino acids, the study showed the following:

Except for histamine and methionine + cysteine, the mean intakes for the test group overall is more than twice as high as the WHO recommendations. Compared with the recommendations made by MIT/Young et al. (table 6.20, page 138), the mean average lysine consumption of the raw foodists overall and the male raw foodists is just below the requirements. All of the other amino acids are covered [217-135].

For isoleucine, leucine, valine, lysine, threonine, tryptophan, and phenylalanine + tyrosine, the consumption of essential amino acids is above the WHO recommendations for all participants.

Even when applying the conversion to mg/kg at least 90 % of participants reached the recommendations for all essential amino acids. For some essential amino acids (at least 95 %), consumption was actually twice the amount recommended by the WHO.

However, as part of the discussion the following statement was made [217-141]: For two Swedish studies on vegetarians and vegans [Abdulla et al., 1984, Abdulla et al., 1981], the quantities of the respective essential amino acids were determined analytically.

A comparison of the range of data collected is difficult. It shows, however, that a raw food diet has a lower content of three essential amino acids (leu, lys, and thr) and of methionine + cysteine in comparison with a vegetarian diet.

What can we learn from this? That raw food vegans are worse off than vegans who eat cooked food?

As far as protein, the mean value of serum albumin was 42 g/L. These values are also within the normal range of 25 to 50 g/L for vegan raw foodists. Transferrin was at 2.89 g/L overall for the test group and within the standard range of 2 to 4 g/L. The mean total level of protein in the blood plasma of the participants was 72 g/L and therefore within the reference range of 65 to 82 g/L.

The uric acid levels

The uric acid levels were within the reference level of 3.4 to 7.0 mg/dL for 90.5% of the raw foodists.

Detoxification of the resulting ammonia in protein metabolism is accomplished through the major end product urea. 87.1% of the raw foodists have urea levels within the reference levels of 10 to 50 mg/dL. The remaining participants have levels almost exclusively below this. That, of course, is good news.

Reduced glucose levels were not recorded for the raw foodists. 89% of them are within the reference levels of 60 to 100 mg/dL. None of the participants have values below this. A requirement for being able to defend oneself against cold temperatures is the availability of thyroid hormones in sufficient quantities.

T3 is reduced during periods of fasting and as a result indirectly works to regulate temperature. In the psychological questionnaire, the most common aches and pains that the raw foodists mention are cold feet/hands.

Redaction comment

T3 denotes the conversion of thyroxine (T4) into the active triiodothyronine (T3). Its reduction causes the basal metabolic rate to decrease, thus saving energy. (See Ernährung und Fasten als Therapie (Nutrition and fasting as therapy, in German only), by Rainer Stange and Claus Leitzmann, Springer 2010, 317 pages).

In spite of these generally good values, the study used blood counts to contend that 43 % of the male subjects and 15 % of the female subjects were anemic [Kwanbunjan et al., 1996, Kwanbunjan 1996 p.124]. For example, the author compared the reduced serum triglyceride levels with PEM and concluded that protein-energy malnutrition (marasmus) must be present.

However, at 65 mg/dL, these values are within the lower reference range of 60 to 200 mg/dL. In addition, for some significant values such as electrolytes, vitamins A, B2, and C or the immune system vegans tend to have values that go in the opposite direction of PEM (protein-energy malnutrition) [217-53ff].

The study then concludes:

As all participants have serum creatinine levels in the reference range (0.7 to 1.3 mg/dL for men and 0.6 to 1.2 for women), it can be assumed that renal function is intact.

Aflatoxins were discussed as a factor in the etiology of kwashiorkor, that is PEM (protein-energy malnutrition), as these occur at higher levels in nuts. Menstruating women may miss their period, but this is more likely to be observed in undernourished / anorexia nervosa patients — the explanation here is a bit vague [217-156].

The following is from the final conclusion. That pretty much says it all ...

The Giessen Raw Food study is a cross-sectional study that measures prevalence instead of incidence. It is therefore difficult to establish a relationship between a raw food diet (exposure) and deficiencies (outcome) or to interpret such a relationship.

Cover of "Rohkost - die lebendige Nahrung" by former gourmet chef, Urs Hochstrasser, Switzerland.© CC-by-sa 2.0, Photo Ernst Erb, Foundation Diet Health

A former gourmet chef, Urs Hochstrasser, from the School of Life in Flüeli-Ranft, Switzerland, provides readers with guidelines and tips for eating a raw food diet. He also gives courses.

For religious reasons, he is very much against eating meat. He has an interest in Kirlian photography and includes numerous recipes that incorporate sprouting and sprouts.

2.6. My closing remarks

This study is a very comprehensive work that took much time and effort to conduct and for which numerous assistants were required. The publication is for scientific purposes only and is not intended for laypeople. This explains why the study consists largely of a series of data and statistics from other studies, reference statistics, and comparisons. For this reason, it would have actually been nice if the book had an index.

It is good that this certainly valuable study was able to reach its intended audience. But at the latest at this point, this very in-depth analysis should have been supported by a synthesis.

The study examines and discusses individual parameters quite comprehensively and accurately in as far as they relate to nutrition and human metabolism. But unfortunately there are a lot of quotations from an overwhelming number of scientific works and only brief statements to introduce and/or explain these.


For example, the study compared the average daily food intake of the participants in regard to more than 30 parameters with the recommendations made by the German Nutrition Society [217-206ff]. However, the subjective and objective health of the participants did not seem to be of interest.

Example on page 71: BCM (body cell mass) is the sum of the oxygen-consuming, potassium-rich, glucose-oxidizing cells. BCM includes the cells of the muscles, the internal organs of the gastrointestinal tract, the blood, the glands, and the nervous system.

BCM is the key parameter used in assessing the nutritional status of the participants since all metabolic processes of the organism take place within BCM cells. The ECM (extracellular matrix) is a collection of extracellular molecules secreted by cells that provides structural and biochemical support to the surrounding cells.

... Malnutrition associated with changes in TBW [total body water] can be diagnosed by changes in the BCM and ECM [Kuhn et al., 1989].

Readers therefore learn how science assesses a person’s nutritional condition. The study compares the health of raw foodists with that of people on a “normal” diet. It does so without taking into consideration the fact that when a person is on a raw food diet their body works “very differently,” in particular, because of the low amount of animal protein they consume.

For raw foodists, actual consumption of the “essential molecules" (those not made by the body) is several times greater and the “usage” of these is significantly lower.

The official values are actually based on unnaturally low absorption (or resorption) and usage of nutrients as is the case for people on a “normal” diet, and they also include high safety margins.

Many comparisons were conducted between these groups in regard to certain parameters; however, what was not taken into consideration was whether the individuals were healthier, more alert, or more energetic or whether they would live longer, how they felt, or how their bodies truly functioned.

On the contrary, the similar slim appearance and partly similar internal structure of the vegan raw foodists resulted in superficial comparisons with people from Sierra Leone and Ecuador [217-105]. This reminds me of conditions in the Sahel region.

For raw foodists, this practically constitutes an insult rather than being in any way helpful

Such a comparison would have been more appropriate if at the same time health and/or fitness had been included in the investigation, of course, taking into account hygiene and medical facilities on both sides.

On page 148, we read: In a study of a group of 23 participants who followed the Living Food Diet for one week and a control group of 15 people who consumed the same [sic!] food that had however been cooked for two minutes in the microwave, there were differences in the total protein status [Hänninen et al.,1992].

We also read: Some parameter values of the raw foodists were consistent with those of PEM (protein-energy malnutrition)” [217-164]. Or: “Based on the reports, it APPEARS that some of the parameters examined for the raw foodists were equivalent with parameters of PEM or anorexia nervosa.

Although the group overall does not show any signs of a pronounced deficiency, the likelihood of these is of concern [217-159].

For raw foodists, who are generally more well-off than the general public (e.g., education and income), this practically constitutes an insult rather than being in any way helpful.

The study therefore infers that a large group of educated and financially independent Germans do not have the ability to assess their own state of health. These people must be somewhat foolish since they have chosen to live differently and more consciously. Sounds a little disrespectful, doesn’t it?

But readers will also find some positive comments such as A number of people reported positive experiences eating a raw food diet. The immediate response was, Well, for people who previously ate a rather typical “Western” diet, that is really not surprising [217-160].

Now, why is this not surprising? It should actually be quite surprising that the study compares raw foodists with PEM or anorexia nervosa (anorexia) or with people from Sierra Leone, even if the following sentence states:

Eating a high proportion of unheated foods CAN very well have a beneficial effect. Fresh food provides many nutritional benefits. This includes a high concentration of essential nutrients, especially the partially heat-labile or volatile oxygen-sensitive phytonutrients.

And another positive finding: Chewing well and salivation also have a positive effect on our gums and digestion. And another benefit is that very few (essential) amino acids are lost as a result of heat damage, the Maillard reaction, and other processes.

However, the presence of protease inhibitors is a clear disadvantage as these can cause damage to endogenous protein and other substances and can only be inactivated by heat or processing [217-161].

Photo from cover of "The Hippocrates Diet and Health Program", Ann Wigmore, 1984, USA.© CC-by-sa 2.0, Photo Ernst Erb, Foundation Diet Health
Ann Wigmore (1909–1994) is the best-known proponent of a pure vegan raw food diet. As a very active woman, she died at age 85 of smoke inhalation from a fire at the Ann Wigmore Foundation. She is known primarily for her wheatgrass and barley grass drinks. Today, these often just come under the category of green smoothies.

But we as “consumers” tend to forget that a study is allowed to be biased in its investigations and reports, instead of helping those who are paying for it — namely, consumers and taxpayers.

It would have been very useful if the study would have provided advice for the “risk groups.” Even with a vegan raw food diet, it’s easy to rule out possible malnutrition.

Unfortunately I must admit that with raw food diets in particular there are numerous obscure views that can eventually lead to malnutrition.

For every type of diet, you can find people who have physical or mental disorders and therefore do not benefit from their nutrition or — more commonly — practice really senseless diets, which then naturally also get included in the statistics.

What would have also been positive to be discussed in this book

The very comprehensive and excellent questionnaire could have turned up this type of findings, particularly for points 2.8 (type of diet) or 2.12 which asked Do you intend to stay with your current diet? and provided five possible answers to select from.

It would have also been positive if point 2.14 had been discussed in this book. Point 2.14 asked the question Which of the following reasons for preferring a raw food diet over other diets is most important to you? and had eight possible answers.

Question 5.4 also asks about the reasons why the participants changed over to a raw food diet.

Question 5.8 could have provided a lot of information about conditions that either disappeared or appeared after the participants changed their diet.

And 5.9 (cancer), 5.10 (allergies) and 5.11 (diseases), and 5.12 (bowel movement) would have been easy to evaluate and discuss.

Fortunately, however, one thing that you will not find in this study, for example, is that the bioavailability of some substances in a purely vegan diet is very limited, without stating at the same time that there is a far greater occurrence of these nutrients in vegan foods.

Oversupply of beta carotene

The study notes, for example, that many participants had an oversupply of beta carotene, but corrects it then with the following statement: However, that supply is mainly from raw foods where bioavailability is not as high as from gently cooked food [217-96] This is a poor general verdict.

Those who eat a “normal” diet and overcook their foods instead of gently cooking them can also be deficient in nutrients. However, the study was not intended to identify disadvantages of eating cooked foods.. That is clear and how it should be.

Carola Strassner therefore did not make the error of confusing the excessive beta-carotene supply (provitamin A) with a dangerous oversupply of vitamin A, as others have done.

But it always amazes practicing and aware raw foodists how young people in the medical field are often convinced by clichés and practice selective perception. They don’t consider the fact that a disease may have been the reason that a person changed their diet in the first place.

They are not able to recognize the fact that nature itself made sure that this diet — which is not always accepted by the medical community — produces people who don’t stand out for being overweight but instead for their athletic achievements or other activities. Numerous prominent vegetarians have shown us this. For example:

These are all vegetarians. You can also see this long list of celebrity vegans.

Some do not realize that humans have “grown” from their diet for millions of years, just like other living creatures. People will dissect and blindly trust statistics that they didn’t falsify themselves rather than life itself.

I know that such a work requires a special degree of meticulousness, accuracy, and diligence, and this work here has been done extremely well in many ways. However, as a book (available on it should also take holistic aspects into account, especially when the questionnaire asked the participants specifically about these aspects. But I guess this would have been the opposition to the clear purpose of the study.

References, which would likely leave inexperienced readers confused and overwhelmed

Nevertheless, on page 157 we read the following: The recommendations for nutrient intake should not be confused with the nutritional needs of an individual as the recommendations usually account for a substantial safety margin (2SD), which is supposed to compensate for individual variations.

The study is full of such references, which would likely leave inexperienced readers confused and overwhelmed. [+2SD stands for security surcharge. This is an increase of figures by 25% to compensate for variance (sample variance), in other words individual differences (disparity, otherness). See analysis of variance.]

The study as a book would have been very useful if it had provided effective advice, but the contributors probably lacked the necessary experience.

Although it is mentioned at the beginning of the book, I feel that the analysis of this diet should have included a more detailed discussion of how our body has a very flexible response system.

There is a thorough description of the body’s excellent regulators, for example, about changes in resorption, the slow adaptation of the body, and the rapid regulatory role of homeostatic mechanisms.

The effective values of true raw foodists can therefore be proven in many aspects in a different manner than can be done with control groups that eat a “normal” diet.

The question that arises is why there is a large discrepancy between the values determined for those on a “normal” diet and those on a raw food diet. And also why the raw foodists are on average in better health and — as far as I have seen — have a better outlook on life. This at a BMI that science denotes as being the ideal biological weight but that this study describes as “malnutrition.”

As described in the study, most of the participants said that they were on a raw food diet for health reasons. And interestingly the multi-volume work Ernährungslehre und Diätetik (Nutrition and dietetics)[31], which was authored at JLU Giessen, focused on such relationships, even if this work is outdated in many respects.

The study therefore comes from the “right institution,” and it provides detailed information for nutritionists and even for laypeople. At the beginning, it gives factual and balanced information, including the latest findings in the field of nutrition. However, in terms of occurrence and implications, it comes to biased conclusions.

The verdict made is mild but “black and white” instead of differentiated and balanced.

It seems as though a number of positive findings from the study did not find their way into this book or weren’t permitted to.

3. About the book

Title Is a Raw Food Diet Healthier?
Subtitle The Giessen Raw Food Study
Author Carola Strassner
Publisher Verlag für Medizin und Gesundheit
Publication 1998
Pages 243
ISBN 3-932977-04-1
Note Only available in German. Ms. Strassner is now Prof. Dr. oec.troph., MBA. [217-??] = internal. book no. (oec. troph. = nutrition specialist)


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