80/10/10 versus science

‘The 80/10/10 diet’ is a book written by Douglas N. Graham, which suggests that a diet for optimal health should consist primarily of carbohydrates (80% of consumed calories) and contain only small amounts of fat and protein (maximal 10% for both).

Reading this book I found several statements I highly disagree with. In this text, I would like to address some of them, supporting my arguments with statements from scientific literature.

Some of the points I make apply not only to the 80/10/10 diet but also to other raw or high carbohydrate diets.

I will address following topics:

1. Nutrient ratio (80/10/10) and dangers of low protein/fat diets

2. Why eating a raw food diet is neither ideal nor necessary for good health

3. Misinformation about ketones

4. Irrational recommendations for optimal bodyweight

Nutrient ratio (80/10/10) and dangers of low protein/fat diets

Carbohydrates

Graham recommends 80% carbohydrates or even higher for most post people. A possible danger of such diet is that chronic consumption of a low fat, high carbohydrate diet may result in the inadequate intake of certain essential nutrients, as described by the instate of medicine¹.

Graham warns that “insufficient carbohydrate in the diet leads to an array of health concerns, primary among which are eating disorders, severe food cravings, lethargy, weakness, and all of the conditions associated with the overconsumption of fats”. In my opinion, all these ‘problems’ don’t apply to individuals eating a balanced diet that provides enough calories.

The 80/10/10 diet doesn’t advise the consumption of all carbs. It excludes insoluble fibers found in starchy vegetables, grains, and beans arguing that we lack digestive enzymes to digest.

Although, it is true that we don’t produce enzymes to digest fiber, it is not a problem. The microbes in our gut do this job. Gut bacteria consume fiber and produce molecules (propionate for instance) that are beneficial to our health⁵.

According to Graham, insoluble fibers should not be eaten, because they are “are extremely harsh on our delicate digestive tracts”. Interestingly, insoluble fiber and fiber from cereal and vegetable sources have been shown to be beneficial for our bodies. They are inversely associated with risk of coronary heart disease, cardiovascular disease risk and prostate cancer risk^{6 8}.

Also consumption of insoluble fiber was suggested to improve digestive feelings, general wellbeing and bowl function in a dose dependent manner⁷.

Protein

Graham claims that more than 10% of calories from protein leads to risks such as osteoporosis, kidney disease, etc. I reviewed the possible dangers of a high protein diet in the past².

There is no scientific evidence I am aware of showing that high protein diet leads to negative health effects for healthy individuals.

In Graham’s opinion, near-double safety factor of the U.S. RDA is met when a low protein diet, consisting of about 5% of calories from protein, is followed. The fact that is not mentioned here is that RDA is the MINIMUM daily average dietary intake level that meets the nutrient requirements. It is not the nutrient intake that makes most people feel and perform at their best.

RDA is the nutrient intake at which the risk of inadequacy is very small (2-3%). Decreasing protein intake below RDA guidelines increases the risk of deficiencies¹.

Sufficient protein intake isn’t only important for muscle hypertrophy but also for many other important processes in the human body. Organs and bone tissue consist of protein, for one. Further, enzymes, antibodies, and hormones, have vital functions and are negatively affected by poor nutrition¹⁰

Fat

Graham states that more than 10% of daily calorie intake from fat lead to different diseases, such as cardiovascular disease, diabetes, etc. Interestingly, recent systematic review and meta-analysis found out that high fat diet is more beneficial than low fat diet for pre-diabetic and diabetes type 2 patients³.

In particular, the consumption of vegan fat sources, such as vegetable oils, including non-hydrogenated margarines, nuts, and seeds, is recommended for prevention of type 2 diabetes⁹.

Also, for patients at high cardiovascular disease risk, a Mediterranean diet plus olive oil reduced new-inset diabetes more than a low-fat diet⁴. Reduction of dietary fat to 10% may actually worsen lipid profiles in certain populations¹⁰.

Fats have many important functions in the human body. Fats are essential building blocks for many molecules and are important for the absorption of fat-soluble vitamins A, D, E and K and carotenoids.

Essential fatty acids are required for the formation of healthy cell membranes, proper brain and nervous system development and function and hormone production. Insufficient fat intake can lead to scaly skin, dermatitis, reduced growth, and in some populations to hematologic disturbance and diminished immune response^{1 10}.

Eating a low fat diet (less than 15% of calories) can harm health and athletic performance. Institute of Medicine recommends for the general public that 20-35% of total calories consumed should come from fat. Fat guidelines for individual athletes may be higher to optimise their performance¹⁰.

Why eating a raw food diet is neither ideal nor necessary for good health

In this part I will give citations from the book and comment on them:

Claim: “Raw foods make a lot of common sense, and the sciences completely support the raw-food concept. Unfortunately, the doctors and scientists who study nutrition, for the most part, are cooked-food eaters, and they see the world through a cooked-food perspective. They cannot see beyond their accustomed view to envision another approach.”

Reality: In this passage several claims are made and scientists are accused of being blind to the facts. However, no real scientific evidence is provided to support a raw diet. In contrast, I will provide a citation from a peer-reviewed research paper to show that a raw food diet is associated with dangers.”We note that modern raw foodists who eat meat and high‐quality plant products experience such high rates of chronic energy deficiency, despite processing their foods heavily by nonthermal means, that a majority of females experience subfecundity. This finding suggests that, in humans, the caloric gains conferred by cooking may be not merely advantageous but also necessary for normal biological function”¹¹.

Claim: In terms of human evolutionary history, 10’000 years is an extremely short period of time, not nearly enough for our digestive physiology to have adapted to the kind of wholesale degradation that cooking causes to our food. [….] we could not adapt in a healthful fashion to the nutritional losses or the toxins created by cooking food”

Reality: Here again, claims are made without providing any references to support them. We had more than enough time to adapt¹². Evolution lead to gene emergence in humans that encode enzymes for starch-digestion (amylases)¹³. I will address the toxin argument later in this section.

Claim: Many foods that are cooked, such as meats and grains, would otherwise be unappetizing or inedible to humans. Cooking allows foods to bypass sensory safeguards that would normally protect us from ingesting unnatural and unhealthful substances.”

Reality: Cooking food allowed ancestral humans to thrive by consuming more calories. This resulted in increases in activity, birth rate, body size, and brain size¹¹. This is the reason we have civilization and don’t live in forests any more. Inactivating toxins by cooking was a pretty useful thing for the survival of our species.

Claim: High fat content is another common problem with cooked foods. In particular, meats, grains, and other starchy foods often contain far more fat than is healthful. The fat is not always visible, however. It is absorbed into starchy foods in the cooking process. Fried potatoes don’t look fatty; we like to think of them as a carbohydrate food. Yet the average serving of fries provides about half of its calories from fat. Apple pie, you would think, is all carbohydrate, right? It is made of sugar and apples and a grain-based crust, all high-carbohydrate foods. Think again, as this delicacy tips the scale at 50% of calories from fat. Not even a baked potato qualifies as a low-fat food, once we add butter or sour cream.”

Reality: “…grains, and other starchy foods often contain far more fat than is healthful.” No, they definitely don’t. If you add fat to food, then the fat content increases. This is common sense. There are many recipes for low fat starchy food. For this reason, this argument is not valid.

Claim: The repeated consumption of cooked food results in a detrimental enlargement of the pancreas, as well as damage to the liver, heart, thyroid gland, adrenals, and most other organs, as a result of toxic exposure combined with reduced oxygen availability.”

Reality: Once again, Graham makes claims without supporting his statement with scientific references. As I already mentioned and referenced above, cooked food made ancestral humans thrive and survive¹¹. Nevertheless, I would like to address one of the points, thyroid for instance. Actually, cooking inactivates goitrogenic compounds that can affect thyroid function. These compounds are present in many raw vegetables (especially, cruciferous veggies) and some fruits. For this reason, cooking of certain foods is beneficial for thyroid function.

Claim: Eating cooked food has also been shown to provoke degenerative changes in almost all aspects of blood chemistry. These changes usually reverse rapidly when exposure to cooked food is eliminated. Studies have shown that our immunes system often reacts to the introduction of cooked food to the bloodstream the same way it does to foreign pathogens such as bacteria, viruses, and fungi: The body literally attacks the food, sending an army of white blood cells to do the job. This phenomenon, which has been linked with the eventual development of AIDS, does not occur when we eat raw foods.”

Reality: The phenomenon Graham refers to is so called digestive leukocytosis. In the 1920 researchers found that the number of white blood cells (leukocytes) increases after a meal. White blood cells are involved in body’s immune response.

First it was postulated that the reason for it is the consumption of cooked foods. However, a later study performed in 1931 could not conform this hypothesis and concluded that the fluctuation in the leukocyte number are random and fall within the normal range of leukocyte count¹⁴.

More recent studies, have shown that white blood cell number increases after eating food high in protein and/or fat. For this reason, it is not conclusive whether the changes in blood chemistry are caused by these macronutrients or by cooked food^{15 16 17}.

Interestingly, exercise was also shown to increase white blood cell count¹⁸. Exercising is in general associated with health benefits. For this reason, I think that the increased white blood cell number seems to be normal response of the body to certain conditions. The last statement of the citation above is highly misleading, in my opinion.

Eating cooked food does NOT cause AIDS (acquired immune deficiency syndrome). AIDS is caused by the human immunodeficiency virus (HIV). HIV can be transmitted when bodily fluids, such as blood, semen or vaginal fluids, from an infected person enter the body of another person¹⁹.

Claim: “A direct cause-and-effect correlation exists between the cooked-food diet and American culture’s two main killers, cancer and heart disease. Many of these relationships have been documented for decades, and the evidence is mounting. Obesity, is directly associated with cooking our food. Heated foods are nutritionally inferior, which is one of the reasons people commonly overeat cooked food. Their stomachs feel full, but their cells crave nutrients and remain nutritionally starved.”

Reality: Correlation is not causation. If a person doesn’t care about eating healthy, then poor health results from poor diet and not the fact that the food is cooked. Indeed, cooked food is calorie denser. However, eating cooked, healthy food (veggies, grains, etc) in reasonable amounts does not cause the described problems, in my opinion.

Claim: But few people realize that cooking denatures the proteins in foods, fusing the amino acids together with enzyme-resistant bonds that preclude them from being fully broken down, thus rendering the proteins substantially useless – and in fact toxic - to us. Our digestive enzymes cannot easily break down coagulated protein molecules once they fuse together. The best they can accomplish is partial breakdown, into polypeptides. The body recognizes clumps of partially broken down proteins, known as polypeptides, as foreign invaders to be attacked, contained, and eliminated through the kidneys. The cell walls of the kidneys do not allow for easy transport of these substances, and their buildup causes the distress that leads to kidney stones and eventually to kidney failure.”

Reality:

1. Regarding useless – Cooking helps us to extract more energy from food (in this case protein), which helped our ancestors to survive. Citation from scientific literature to support my statement: “we show that cooking substantially increases the energy gained from meat, leading to elevations in body mass […]. The positive energetic effects of cooking were found to be superior to the effects of pounding in both meat and starch-rich tubers, a conclusion further supported by food preferences in fasted animals. Our results indicate significant contributions from cooking to both modern and ancestral human energy budgets.”¹¹

2. Regarding denaturated/coagulated proteins are difficult to digest – I think this argument addressed mainly meat consumption. Although this is not a concern for vegans, similar protein coagulation might occur when ‘fake meat’ is cooked. However, even for meat this argument is not right. Cooking makes proteins easier to digest. Citation from scientific literature to support my statement: “We propose three candidate mechanisms for the positive effects of cooking observed in this study. First, consumer-specific digestibility may have been improved through heat-induced denaturation of protein. In this process, proteins unwind from their tightly bound structures when heated, adopting a random coil configuration that increases their susceptibility to proteolytic enzymes in the small intestine before access by gut bacteria.Second, diet-induced thermogenesis may have been reduced because of the compromised structural integrity of cooked meat. Although heat tends to toughen muscle fibers, it gelatinizes the collagen in the muscle matrix, easing separation of muscle fibers. This separation facilitates mastication and increases the surface area of meat exposed to gastric acids and enzymes. Reduced structural integrity was the mechanism advanced to explain why pythons experienced 13% lower diet-induced thermogenesis after meals of cooked vsraw meat. Third, cooking may have killed pathogens present in the meat samples, reducing the metabolic cost of immune defense.”¹¹

3. Regarding kidney stones/failure:There is no scientific evidence, I am aware of, that shows that high protein consumption leads to kidney failure/stones in healthy individuals. One of many citations from scientific literature to support my statement: “At the present time, however, evidence showing that a high protein intake is an inherent cause of this renal abnormality or is consistently associated with increased kidney stone formation does not exist.”²⁰

Claim: “We must heat starchy carbohydrates to “dextrinize” them, thus facilitating their breakdown into glucose. Unfortunately, heating caramelizes these complex carbohydrate foods, fusing their molecules into a sticky, molasses -like goo.”

Reality: I don’t see any problem with the process described above.Citation from scientific literature to support my statement: “Heat gelatinizes starches, transforming resistant semicrystalline structures into amorphous compounds that are readily hydrolyzed to sugars and dextrins, resulting in higher consumer-specific digestibility.”¹¹

Claim: “The digestion of cooked complex carbohydrates is typically impaired by the fatty and sugary foods with which they are consumed, leading to fermentation. The byproducts of fermentation are gas, alcohol, and acetic acid. Alcohol is a protoplasmic poison that kills every cell with which it comes into contact. Acetic acid in its pure form is a known poison. When diluted with parts water, it is called vinegar. The acetic acid in vinegar is still toxic, regardless of dilution.”

Reality: “The dose makes the poison” I am not aware of any case where the addition of vinegar to salad dressing has killed a person.

Claim: “Of great concern is “acrylamide” recently discovered to be produced in high-carbohydrate foods by the chemistry of cooking. This potent chemical killer was found in high concentrations in the food supply in 2002 by a Swedish researcher. High levels of acrylamide are found most prominently in bread, chips, crackers, french fries, and other dry-cooked carbohydrates.”

Reality: First of all, not all cooked food contains acrylamide (see citation for more details). Secondly, there is not enough evidence that shows that acrylaminde causes cancer in humans. In general, it is beneficial to avoid calorie-dense and nutrient-poor food, such as chips and french fries, because it is not healthy in particular and not because it is cooked.

Citations from scientific literature to support my statement: “Carbohydrate-rich foods such as French fries processed/ cooked at high temperatures and under low moisture conditions were predominantly of concern. No acrylamide was found in raw and boiled foods.” “Recent epidemiological studies failed to evidence an association of cancer incidence and dietary acrylamide exposure.The weight of evidence for the carcinogenicity of acrylamide in humans is based primarily on animal data. In occupational exposure studies of human workers, no significant increase of cancer risk or cancer mortality was observed. Furthermore, two retrospective studies on the association of cancer incidence and dietary acrylamide exposure in Sweden and Italy/Switzerland could not provide evidence for an association between high and low dietary acrylamide intake and cancer incidences of various organs.Because the cancer risk posed by acrylamide cannot reliably be calculated quantitatively to date, the WHO has not recommended a general change in dietary habits, except to advise that foods should be cooked not excessively, but thoroughly to destroy pathogens and that consumers should eat a balanced and varied diet.”²¹

Claim: “Heated fats interfere with cell respiration, leading to cancer and heart disease. Heating fats also reduces the functional value of their antioxidant properties. Once fats have been cooked, they quickly go rancid, at which point they become carcinogenic. Thus, it’s important to understand that while even freshly roasted nuts are harmful for us, they become more so the longer they sit out.”

Reality:

1. I searched through scientific literature in order to find association between heated oil and cancer. I couldn’t find that eating heated fat causes cancer. The only thing I found is that inhaling cooking oil fumes can cause cancer²² and that some populations in Africa have a higher odd of a rare cancer that might be caused by consumption of some specific foods (such as rancid butter and rancid sheep fat)²³.

2. Antioxidant properties can be indeed reduced by heating. However, individuals eating a healthy diet (fruits, veggies,..) are likely to consume enough antioxidants. For this reason, there is no need to relay on fat as antioxidant source, in my opinion.

3. Indeed, rancid fat should not be consumed, as it might lead to foodborne disease (vomiting, abdominal pain and diarrhea). However, in most cases it is ‘difficult’ to consume rancid food because of its disgusting smell/taste²⁴.

Claim: “Many high-temperature methods of cooking (deep frying, broiling, roasting, barbecuing to a char, etc.) cause fats to produce carcinogenic substances including acrolein, hydrocarbons, nitrosamines, and benzopyrene, which is one of the most virulent carcinogens known to man.”

Reality: Most some of theses substances are carcinogenic when inhaled (oil fumes) and not eaten. Others are found mostly in meat and only in very low amounts in vegan foods. In my opinion, the claim made doesn’t apply to individuals eating a healthy, vegan diet.

1. Acrolein: “Similarly, cooking in poorly ventilated kitchens has been associated with respiratory illnesses, weakening of the immune system, and lung cancer in rural China. It is conceivable that acrolein is co-responsible for these effects.”²⁵ “The high concentration of carcinogens,[…], in cooking oil fumes might help explain why Chinese women, who spend more time exposed to cooking oil fumes than men, have a high incidence of pulmonary adenocarcinoma.”²⁶

2. Nitrosamines – mainly in meat. However, there might be a correlation between cancer and preserved vegetables (pickled, for example) “Our findings suggest that high consumption of processed meat may increase the risk of stomach cancer. Dietary nitrosamines might be responsible for the positive association.”²⁷ “The available evidence supports a positive association between nitrite and nitrosamine intake and gastric cancer, between meat and processed meat intake and gastric cancer and oesophageal cancer, and between preserved fish, vegetable and smoked food intake and gastric cancer, but is not conclusive.”²⁸

3. Benzopyrene – found mainly in grilled meat. Although, benzopyrene was also found in some vegan foods, the amounts were much lower (almost 100-times) than in animal products. “The highest levels of benzo[a]pyrene (BaP) were found in grilled/barbecued very well done steaks and hamburgers and in grilled/barbecued well done chicken with skin. […] The BaP levels in non-meat items were generally low.”²⁹ “Higher levels of BaP were detected in fried chicken (5.25-5.55 BaP microg/kg) and smoked dried beef (5.47 microg/kg) compared to relatively lower levels measured in sesame oil (0.36 microg/kg) and peanut (0.44 microg/kg). The BaP levels in nonmeat items were generally low in detection, but certain potato chip products showed levels up to 4.06 BaP microg/kg.”³⁰

Misinformation about ketones

Citations from the book:

Claim 1: “When we do not eat sufficient carbohydrates to meet our fuel needs, our bodies break down stored fats into glucose through a complex chemical process called gluconeogenesis (literally, “the creation of new sugar”). While this can be a lifesaving process in times of hardship, in the absence of sufficient carbohydrates, gluconeogenesis results in the production of by-products known as ketones.”

Claim 2: “Circulating in the bloodstream, ketones adversely affect our decision-making abilities, because they exert an influence upon brain chemistry similar to that of alcohol. Effectively, a heavy ketotic state renders us “under the influence.” In such a state, we should not make decisions important to our life and health, such as those made when driving a car, doing sports, or performing any work that requires precision of body or mind.”

Claim 3: “But when one’s body runs out of carb fuel to burn, its only choice is to burn fat inefficiently using a pathway that produces toxic by-products like acetone and other so-called ‘ketones’.”

Reality: First of all, I would like to correct the first statement: “When we do not eat sufficient carbohydrates to meet our fuel needs, our bodies break down stored fats into”… an activated form of acetic acid, called acetyl-CoA (NOT glucose).

Acetly-CoA is either used to make glucose (gluconeogenesis) or to produce ketones. Ketones are NOT by-products that are formed during gluconeogenesis.

Ketones are important energy sources in the human body³¹. Indeed, some tissues/organs, such as heart muscle and the renal cortex prefer ketones to glucose.

On the other hand, our brain prefers glucose, although it can utilize ketones as energy source (75% of fuel needs) when glucose is not ingested for a longer time period. This leads me to the second claim from above saying, that ketones negatively affect the brain function.

Indeed, difficulties thinking/focusing (aka “brain fog”) may occur in the first 2 weeks when people adapt a very low carb diet (ketogenic diet, less than 60 g carbs a day). However, then the body adapts to a ketogentic diet³².

Another wide spread belief is that our bodies need carbs to perform. This is definitely true to some extent. However, a recent study showed that ketogenic diet did not affect strength performance in elite artistic gymnasts³².

In my opinion, dependence on carbs is highly sport and individual specific. Women, for example, rely more on fat than carbs as energy source compared to men³³.

Whereas, I wouldn’t suggest a ketogenic diet to an endurance athlete, a low carb diet may be a good strategy for a strength athlete, especially for a cutting cycle.

Irrational recommendations for optimal bodyweight

According to Graham, a healthy body-fat percentage for a man is between 3-9% and for a woman 13-19%. He argues that dropping body fat below this level can lead to eating infertility and hormonal imbalances in women.

However, the body fat percentage of 13-19% for women is reasonable low, present mostly in athletic individuals. Reproductive dysfunctions are common in female athletes partly because of their low body fat level³⁴. Also, for men 3-9% body fat is fairly low. At this body fat percentage most competitive bodybuilders go on stage.

To decrease body fat to such a low level severe calorie restriction for several weeks to months is required in most cases. In my opinion, although it is acceptable for athletes to achieve specific goals, it shouldn’t be a trend that the general population should follow long term.

Interestingly, healthy lifestyle habits are much more important than body mass index³⁵. Eating enough fruits and vegetables, exercising regularly, consuming alcohol in moderation and not smoking, reduces significantly the risk of all causes of mortality for overweight and obese individuals making them not more likely to die than the normal weight population pursuing a healthy lifestyle.

Also, the same healthy living overweight/obese individuals have a twice-lower mortality risk than people within a normal BMI range who do not adhere to healthy habits.

BMI under the normal range (18.5-25) has a negative effect on health and reproductive potential³⁶. On average, women with BMI under the normal range have up to 20-25% body fat and men up to8-14% respectively³⁷.

According to Graham, a body fat percentage of 10-14% is marginal and above 15% unhealthy for men and of 20-24% and 25% for women respectively. This is clearly in disagreement with research data on general population presented up to date.