Thursday, July 21, 2011

Diet and Female Hormone Balance

High levels of serum estrogens and androgens promote premature menarche, premenstrual symptoms [1], menstrual pain [2], polycystic ovary syndrome, hirsutism, menopausal syndrome, and reproductive system (breast, ovarian, etc.) cancers in women [3].

Asian women and women eating plant-based diets excrete more estrogens via the stool than omnivores, and can have 15-30% lower estrogen levels than women eating omnivorous diets, along with lower risks of all of the conditions above [4 , 5 , 6 ].

The Diet and Androgens (DIANA) trial produced a reduction of insulin resistance, a 4 kg weight loss, a small decrease in estrodiol, and a 20% decrease in serum testosterone in women who adhered to a very low fat, plant-based diet with high intake of whole grains, flaxseed and legumes, and minimal intake of animal products over the course of 4.5 months [7].

Nowak et al reported a dramatic decrease in testosterone levels and hirsutism in a PCOS patient who consumed 30 G daily of flaxseed for 4 months [8 ].

Barnard et al reported a decrease in body weight, duration and intensity of premenstrual symptoms, water retention, and duration and intensity of menstrual pain in 33 women who ate a low fat, vegetarian diet for two menstrual cycles [9 ].

Bagga et al reported a significant decrease in serum estrogens with no adverse effects on menstrual cycling among women who ate an ad libitum diet supplying 10% of energy from fat and 25-35 g of fiber daily [10 ].

Excess stored iron appears to play a role in PCOS and insulin resistance [11], and we have evidence suggesting a role in breast cancer [12].   Meat provides more bioavailable iron (heme iron) than plant foods, and oral contraceptives reduce iron  losses; each of these could contribute to excessive stored iron.

I think the literature gives a  pretty clear picture.  Women eating diets low in fat and animal products, and high in whole plant foods,  generally have lower estrogen and testosterone levels and lower incidences of hormone-related diseases, compared to women eating diets high in fat and animal products.  Certain plant foods, e.g. flaxseed, legumes, whole grains, appear particularly effective at increasing elimination of excess estrogens and androgens.  Clinical trials show that  reducing fat and animal products and increasing plant foods rich in fibers will for many women result in reduced hormone levels.  A reduction in hormone levels will generally result in reduced premenstrual discomfort and dysphoria, menstrual pain, fibrocystic changes, and risk of hormone-related cancers.

From an evolutionary perspective, women performed most of the gathering, and while gathering, they probably nibbled on what they were gathering, so I would suspect that they consumed considerable amounts of plant foods on a daily basis, including various seeds, nuts, fruits, and even fresh legumes (wild peas and beans) containing phytoestrogens, just like other primates.

So here's my hypothesis:  I think it probable that human metabolism is adapted to regular intake of phytoestrogens, meaning that our hormone production pattern proceeds on the genetically built-in premise that phytoestrogens and other plant chemicals will be part of the diet, altering hormone levels.  In other words, our hormone production proceeds with the assumption that phytochemicals will be draining out some of our hormones; its production is adapted to a drain that was constant in the millions of years that our ancestors ate plant-based diets.  When we adopt diets that lack these compounds, while simultaneously increasing intake of other compounds (animal protein and fat) that feed the cholesterol and steroid production system, our own production of hormones becomes excessive, producing disease. 

Wednesday, July 13, 2011

Legumes in Hunter-Gatherer Diets

Did hunter-gatherers eat legumes?

According to Sigrid Leger, author of The Hidden Gifts of Nature, Bushmen ate the following legumes:

Wild Coffee Beans (Bauhinia petersiana):  "The seeds are edible and can be gathered from February until May. The pod is removed, the seeds are put into hot ash for a minute and are cooked in this way. After that the seeds can be eaten just as they are or they are pounded and then eaten."

Marama bean (Tylosema esculentum) "The whole pod is put into hot ash for a short time and removed again. After having cooled down, the pods are opened, the skin of the seed is removed and the seed itself is eaten."

These examples appear to illustrate that the absence of pots and pans in the archaeological record does not serve as evidence that prehistoric people did not eat cereals or legumes.  Anyone who has eaten popcorn or peanuts might realize that people can eat grains and legumes roasted as an alternative to boiled.

According to Brand-Miller and Holt, Australian Aborigines also made use of legumes:

"Although seeds, particularly cereals (seeds of the family Gruminae) are thought to have played only a minor role in palaeolithic diets, they appeared to be important in the diet of at least some groups of Australian Aborigines (AA). Before European occupation, collection of seeds was widespread, particularly in arid areas. It was predominant in the grassland areas of Australia but also in the desert areas where acacia trees (wattle trees) yielded abundant seeds. Grindstones used for seed grinding have been found in many areas."

And:

"It appears that ~ 50 of the 800 species of Acacia (wattle trees) native to Australia were used by AA for food.  Despite the wattle being Australia’s national flower, the seeds are generally unknown to non-AA as food sources. But Acacia seeds are outstanding in their nutrient content, being much higher in energy, protein and fat than any cereal crop such as wheat and rice. Their composition more closely resembles that of the legume family to which the Acacias actually belong."

According to some, legumes are among the neolithic foods that cause disease because of their supposed discordance with human genetics, yet both !Kung and AA appeared to have a high immunity to modern diseases of affluence. 

Saturday, July 9, 2011

The Real Gladiator Diet



Source: U of Texas Course Intro To Greece
What did the gladiators eat?

According to Andrew Curry, author of "The Gladiator Diet," an article in the journal Archaeology, Karl Grossschmidt, a paleo-pathologist at the Medical University of Vienna, did an analysis of bones of gladiators found in an 1800 year old graveyard near Ephesus, in what is now western Turkey.

"Contemporary accounts of gladiator life sometimes refer to the warriors as hordearii--literally, "barley men." Grossschmidt and collaborator Fabian Kanz subjected bits of the bone to isotopic analysis, a technique that measures trace chemical elements such as calcium, strontium, and zinc, to see if they could find out why. They turned up some surprising results. Compared to the average inhabitant of Ephesus, gladiators ate more plants and very little animal protein."
Interesting.  The top athletes, with their lives on the line, ate 'very little' animal protein compared to non-athletes.  According to Grossschmidt, gladiators ate this way to get fat:

"The vegetarian diet had nothing to do with poverty or animal rights. Gladiators, it seems, were fat. Consuming a lot of simple carbohydrates, such as barley, and legumes, like beans, was designed for survival in the arena. Packing in the carbs also packed on the pounds. "Gladiators needed subcutaneous fat," Grossschmidt explains. "A fat cushion protects you from cut wounds and shields nerves and blood vessels in a fight." Not only would a lean gladiator have been dead meat, he would have made for a bad show. Surface wounds "look more spectacular," says Grossschmidt. "If I get wounded but just in the fatty layer, I can fight on," he adds. "It doesn't hurt much, and it looks great for the spectators."

What an interesting hypothesis.  Grossschmidt apparently believes that barley and beans are "simple carbohydrates" that "pack on the pounds" making people fat, and that a gladiator would prefer to be fat than lean and muscular.

I challenge Grossschmidt to consume a diet of barley and beans, with less than 10% of his diet as animal products, for a year, to find out if he grows fat eating that way.  Since cooked barley supplies only about 200 calories per cup, he can look forward to eating 6 cups daily just to get to 1200 kcal.  Add one cup of lentils (230 kcal), 4 cups of cooked kale (280 kcal), 4 ounces of sardines (240 kcal), and an ounce of almonds (180 kcal) and you have a nutritionally dense meal plan supplying about 2130 kcal and more than 11 cups of food.  See if you can eat it all, then enough additional to 'pack on the pounds.'

I also suggest that he produce some evidence that gladitors were fat.  He could spend a little time looking at reliefs and other art depicting gladiators of the time.  I found a good selection online from a University of Texas course, Introduction to Greece, here.  I put one of them at the head of this article.  Those men obviously have little subcutaneous or intra-abdominal fat, with ribs, rectus abdominus, deltoids, and upper back muscles clearly defined; they won't qualify as 'fat' by any standard.

Here are a few more from the same source:







Funny, I don't see any fat gladiators.  I didn't cherry-pick, you can look for yourself here.  These depictions don't look that much different from a modern vegetarian combat athlete, Chris Campbell, who won a bronze wrestling in the 1992 Olympics at age 37:
Source:  Information Processing
You can see how fat and weak Campbell got eating all those "simple sugars."

I can't imagine any reason artists would falsely depict gladiators as lean and muscular, if they really were fat.  I wonder where Grossschmidt got his idea?

Grossschmidt apparently believes that "a lean gladiator would have been dead meat" compared to a fat one. I have to doubt that Grossschmidt has any experience in the fighting arts.  Fat slows you down, making you an easy target.  The goal of a gladiator was to survive, not to put on a good show; only a fool would choose to get fat for battles against armed opponents where you only walk away if you can move faster and hit harder than the other guy.

Grossschmidt also believes that those gladiators had to supplement calcium to their barley and vegetable diet:

"But a diet of barley and vegetables would have left the fighters with a serious calcium deficit. To keep their bones strong, historical accounts say, they downed vile brews of charred wood or bone ash, both of which are rich in calcium. Whatever the exact formula, the stuff worked. Grossschmidt says that the calcium levels in the gladiator bones were "exorbitant" compared to the general population. "Many athletes today have to take calcium supplements," he says. "They knew that then, too."
What? Despite having low animal protein intake, and eating a diet based on 'toxic' neolithic barley supplying much-feared gluten, phytates, and other "anti-nutrients" supposed to interfere with calcium absorption, these gladiators had 'exhorbitant' calcium levels in their bones?  Strong bones in agriculturalists?  How could that happen?

Well, let's see if they needed calcium supplements.  Ephesus lies on the west coast of Turkey, near the mouth of the Menderes River, so I will assume the gladiators ate some fish.  I'll build the diet of barley, lentils, kale, olives, acorns, and sardines, all possible foods for those people.  Here's a nutritional analysis of a hypothetical barley diet with less than 10% of calories from sardines:

Click to Enlarge


As you can see, to get to 3400 kcal required by a large, physically active martial artist using swords, tridents, and similar arms, the barley men would have to eat 10 cups of cooked barley in a day.  Now imagine having to eat several more daily to 'pack on the pounds.'  Good luck with that!

With only 4 ounces of sardines (supplying only 236 calories, less than 10% of total) and two cups of lentils, it supplies 116 g of protein, enough for a 220 pound athlete.  The diet supplies energy in the following  proportions: 70/18/12, carbohydrate/fat/protein. It supplies all required nutrients in adequate amounts (most nutrients at 2-4 times the RDA) except vitamin E, which is 77% of RDA, probably adequate for most people eating a diet this low in fat (71 g/d), but we could boost this by exchanging one cup of  barley for one cup of olives (that brings the vitamin E to 97% of RDA and fat to 22% of calories). 

I also tested 3000 calories of this diet by removing 2 cups of barley.  It became 67/20/13 (carb/fat/pro) and still supplied 110 g protein, enough for a 220 pound athlete.  It still supplied at least 100% of the RDA for all listed nutrients except vitamin E, still at 77%.

Now, back to the 'exorbitant' levels of calcium in these athlete's bones. First, ancient athletes were familiar with resistance training, using all types of heavy objects to increase strength.   Physical training with heavy weapons and other sources of resistance stresses the bones, increasing mineral deposition, so we should expect athletes like gladiators to have high bone mineral density.

Second, humans appear to absorb more calcium from some plants, especially cabbage-family green leafy vegetables, than from milk.  In one study humans absorbed a greater proportion of calcium from kale (and probably similar brassica vegetables) (41%) than from milk (32%) [1]. As an aside, Heaney et al found that humans absorbed calcium from leavened whole wheat bread at at higher rate than from milk [2].

Third, we have evidence from other paleo diet research suggesting that a diet with a high ratio of plant to animal protein may promote greater bone mineral density.  Richman et al compared bones of three aboriginal American populations:  Pueblos, Arikaras, and Inuit [3 ].   These groups had similar genetic backgrounds, all descended from the few humans who first populated the Americas.

Richman et al looked for type II osteons, characteristic of increased bone mineral resorption involved in maintaining physiological homeostasis, such as buffering to maintain the pH of urine in the range safe for kidney tubules.  They found that the Pueblos had the least evidence of this type of remodeling, and Eskimos had four times as many type II osteons as the Pueblos.  The diet of the Pueblos consisted largely (80%) of maize and 90% of plant foods, while the Eskimo diet consisted 90% of meat.  The Arikaras consumed more meat than Pueblo and less than Eskimos, and had twice as many type II osteons the Pueblos.


When I first reviewed this study, I missed the fact that it contradicted the theory that people are less adapted to grains than to meat.  If the antinutrients in grains impair calcium and vitamin D metabolism, the Pueblos should have had the worst bone health because they had the highest cereal grain intake, supposedly blocking vitamin D action and calcium absorption; but in fact they had the lowest markers of resorption. 

We have plenty of evidence that isolated Inuit had severe and early onset osteoporosis [4, 5].  Similar to the Pueblos, largely vegetarian Bantu women eating grain-based diets have extremely low rates of osteoporosis despite very low (200-450 mg/d) intakes of calcium and a high number of pregnancies (~10 per woman) with prolonged breastfeeding [6 ]. 

We have some evidence that a diet with a high ratio of animal protein to vegetable protein increases urinary calcium losses and that this may result in demineralization of the bones [7 , 8 , 9 , 10, among others].  While some consider this research inconclusive so far [11], it seems to me that the bulk of research points in the direction of diets with high ratios of animal protein increasing the risk of bone mineral loss, although the mechanism may be unclear and other factors may modify this risk (resistance training, vitamin D, vitamin K, dietary acid-base ratio, sodium intake, to name a few).  Anyway, it appears possible that the gladiators' high ratio of vegetable to animal protein contributed to their maintaining a high bone mineral density. 

I conclude that a diet of barley, lentils, olives, acorns, green vegetables, and small amount of small fish can provide plenty of calcium, which when combined with hard physical training will produce very dense, strong bones.  Maybe those gladiators did add wood ash or bone meal, but they may have been overdosing on unnecessary calcium, the same way the many modern athletes take unnecessary supplements hoping for greater performance.

Thursday, July 7, 2011

The Progression of Disease According To Oriental Medicine: Part 2

-->
In Part 1 of this series, I presented the overview of the progression:

-->
1. Normal discharge and elimination
2. Abnormal discharge and general fatigue
3. Aches and pains signalling sluggish blood circulation
4. Blood quality decline with chronic discharge
5. Accumulation of excess nutrients in circulation
6. Storage of excess nutrients in various compartments
7. Nervous system disorders
8. Delusion

In that post I also presented what happens in stage 1, health, and stage 2, temporary changes in elimination and physical, emotional, and mental activities as the bodymind attempts to metabolize the excess nutrients.  In this part, I will look at stages 3 and 4.


3. Aches and pains signaling sluggish blood circulation


In Chinese medicine, we have a principle:  "If there is pain, there is impaired flow; if there is good flow, there is no pain."  This encapsulates the direct experience that if anything impairs circulation to any part of the body, that part will suffer some type of discomfort.  From this experience, Chinese physicians realized that if any part of the body suffers from some discomfort, this signifies an impairment of circulation of vital blood, nutrients, fluids, and nerve impulses to that part or associated parts.

(By the way, this principle applies equally to social-political and environmental disorders as well.  Social-political disorders arise from poor circulation of resources, allowing some parts of the body politic to suffer deficiencies while others have excesses, creating tension and inflaming passions.  Environmental disorders arise when one organism monopolizes excessive resources while other organisms suffer deficiencies.)

All assimilated nutrients temporarily affect the composition of the blood.   After meals, we see increases of blood fats, sugars, amino acids, vitamins, and minerals.  The body tries to maintain healthy blood levels of water, fats, glucose, cholesterol, minerals, etc. regardless of diet.  If a meal contributes more of any of these factors than the body can readily manage or easily store, it will temporarily affect blood circulation while the body works to remove the incoming nutrients from the blood and store them in appropriate places.  

However, if a person continuously eats three or more meals daily providing excess nutrition, more than the body can use quickly or easily store in an appropriate location in a non-toxic form, this can result in a more or less continuous overabundance of nutrients in the blood, and that can result in a more or less continuous alteration in blood circulation. 

Most people in industrialized nations have had the experience of eating a large holiday meal (feast) and feeling simply overloaded, sluggish, short of breath, and fatigued afterwards.  This provides a direct experience of how excessive nutrition places a burden upon the body, particularly the cardiovascular system, and the effect can last for several hours or more.  If a person feasts 3 times daily, the cardiovascular system will have to deal with excessive nutrition almost continuously through the day. 

High-fat blood sample. Source: Case Reports in Medicine

As I have discussed here, Western research has also shown that rich, i.e. high-fat, meals increase blood coagulation factors. High-fat meals have been shown to increase platelet aggregation, fibrinogen, factor VII, and other hemostatic factors; meals rich in saturated fats (e.g. butter) having the strongest procoagulant effect, followed by meals rich in monounsaturated fats (e.g. olive oil).(1, pdf

Thus it seems that Western research may support the Oriental medicine perspective that an excessive intake of rich foods can produce sluggish blood circulation.  The thick sluggish blood can’t properly nourish, lubricate, or detoxify the tissues, including the heart and brain.  The tissues don't get enough oxygen, and waste products accumulate faster than they are removed.  These internal changes reach our awareness as aches and pains and disturbances of normal function.

In line with this, Kuo et al found that fat ingestion can induce myocardial pain (angina pectoris) in patients with coronary artery disease (2).  Afaq et al found that patients with excess blood cholesterol had reduced oxygen delivery to the calf muscles and consequent shorter time to claudication, which involves pain in the calves along with decreased ability to walk (3).  Mattson et al demonstrated that dietary cholesterol affects serum cholesterol in a dose-response fashion; a cholesterol-free, 40% fat diet produced average serum cholesterol of 164 mg/dl; adding 126 mg cholesterol produced an average serum cholesterol of 174 mg/dl; 212 mg cholesterol daily raised serum cholesterol to an average of 181 mg/dl; and 317 mg cholesterol daily raised the average to 198 mg/dl (4).  Hunter-gatherers, non-human primates, and wild animals have serum cholesterol levels below 150 mg/dl (5, pdf), showing that nature prefers a serum cholesterol below 160 mg/dl.   

Total Cholesterol In H-Gs and Wild Animals.  Source: 5

 Other populations with high immunity to cardiovascular diseases also have average serum cholesterols below 150 mg/dl,
--> including rural Chinese (127 mg/dl, 6), Tarahumaras (125 mg/dl, 7), and Caucasian men eating macrobiotic diets (147 mg/dl, 8).  Based on this data I have revised my views and now consider anything over ~160 mg/dl excess serum cholesterol.


According to Oriental medicine, the following signs and symptoms all reveal developing, diet-induced blood stagnation:

muscle pain and tension
headaches
menstrual cramps
numbness
moderate aches and pains
intermittent abdominal discomforts
sleep disturbances
breathing problems
heart disturbances
chills and fevers
motion and coordination problems

Due to disturbances of blood circulation to the brain and heart, as this stage develops the individual may also experience more frequent mental and emotional disturbances such as hyperexcitability, worry, insecurity, sadness, depression, frustration, and impatience.

To restore balance at this stage, one must remove the causes, maintain a healthy diet with a negative balance of items taken in excess, take appropriate exercise and rest.

Assuming interruption of this process early in its development, recovery from this stage requires restoring the free flow of blood which will require several days to several weeks of healthy diet and lifestyle.

4. Blood quality decline and chronic discharge

If someone continues to consume an excess of some or all nutrients past stage 3, the blood quality gradually declines because the sluggish circulation slows down removal of wastes from the blood by the liver and kidney. Consequently, the whole bodymind system progresses to chronic illness and development of chronic abnormal discharges.

In general, according to Chinese medicine, chronic blockage of blood circulation generates heat (inflammation) in the blood, which gradually affects the entire body if not corrected.

As excess nutrients in circulation gradually but increasingly impair circulation to the lungs, large intestine, liver, kidneys, and skin vessels and pores, the organs can’t properly detoxify the blood and the blood, in turn, can’t properly nourish, moisten, and detoxify the skin.  

In a healthy condition, the body controls the growth of abnormal cells.  However, when the blood  constantly contains excess nutrients that cells need for growth and replication (amino acids, fatty acids, cholesterol, etc.), and the immune system is impaired by poor circulation and accumulation of toxic wastes, abnormal cellular growth can occur unchecked, producing first benign tissue overgrowths like skin tags, moles, bunions, and so on.  If left unchecked, this process eventually leads to malignant growths.

Thus, skin abnormalities herald this stage of disease. As the skin becomes overburdened with metabolic wastes, skin diseases can develop, often in a step-wise fashion from minor to major.  At first the skin diseases may come and go with more or less inflammation or infection.  If left uncorrected, the underlying systemic imbalance will lead next to more constant and serious disorders, generally in a step-wise fashion:
1. pimples, spots, rashes, moles, warts, bunions, dryness, etc.
2. eczema, psoriasis
3. skin cancer
 
As the blood quality declines, while also containing surplus nutrients, it gradually becomes a favorable environment for microbial or abnormal cellular growth, producing blood disorders progressing gradually in seriousness:
1. chronic infections
2. blood malignancies

Other signs of this stage include chronic nasal discharge or sinus congestion, irregular bowel movements, abnormal sweating, rapid respiration, frequent urination, bad breath, chronic vaginal discharges, and chronic unpleasant body odor, all produced as the body attempts to use every possible channel of elimination to get rid of the excess stuff in the blood, attempting to prevent accumulation of these wastes in the tissues. 


By careful observation, Chinese physicians discovered that when the body gets too hot and dry, it produces thicker, darker, more odorous secretions, and when it gets too cold or damp, it produces thinner, lighter secretions.  Thus, darker, drier, concentrated, hard to expel, strong smelling, and more concentrated urine, mucus, feces, sweat, and odor all indicate a body afflicted with heat that can arise from chronic excessive intake of heating and drying, or yang (pronounced "yahng") foods (e.g. red meat, spices), and clear, copious, more watery, runny, and less odorous urine, etc. all can indicate a body imbalanced by excessive intake of cooling and moistening, or yin (pronounced "yeen") foods (e.g. fruits, ice cream).  A person who overconsumes both types of foods can have a mix of both types of symptoms and signs.

Since the blood serves as the material foundation of the mind, as the blood becomes continuously and progressively sluggish and toxic, more chronic mental and emotional disorders arise, such as nervousness, oversensitivity, depression, hyperactivity, confusion, and disorientation (loss of purpose), along with an increasing sense of alienation from one’s community.

Chinese medicine categorizes foods according to whether they are relatively more yin—or cooling, moistening, and draining—or relatively more yang—heating, drying, and congesting.   In terms of mental-emotional effects, excess intake of more yin items (e.g. ice cream, sugar, fruits) produces a more withdrawn, passive affect,  and excess of yang items (e.g. red meat, spices, greasy foods) produces a more aggressive affect. 

To restore balance at this stage one must eliminate the excess intake, eat an appropriate diet, take exercise and rest, and employ special medicinal foods, drinks, and compresses. Recovery will take from 10 days (for plasma renewal) to 4 months (for red blood cell renewal).

Tuesday, July 5, 2011

Stoned On Fat?

Neuroscience researchers at UC Irvine, , led by Daniel Piomelli, have just announced results of a study done on rats, in which they found that ingestion of fatty foods stimulates the release of endocannibinoids, chemicals that activate the same receptors affected by THC.  According to the UC Irvine news release:

"The process starts on the tongue, where fats in food generate a signal that travels first to the brain and then through a nerve bundle called the vagus to the intestines. There, the signal stimulates the production of endocannabinoids, which initiates a surge in cell signaling that prompts the wanton intake of fatty foods, Piomelli said, probably by initiating the release of digestive chemicals linked to hunger and satiety that compel us to eat more."
In other words, rats eating fats had the munchies.  Feeding rats carbohydrate or protein did not have this effect.  Piomelli offers an evolutionary explanation:

"Piomelli said that from an evolutionary standpoint, there’s a compelling need for animals to consume fats, which are scarce in nature but crucial for proper cell functioning. In contemporary human society, however, fats are readily available, and the innate drive to eat fatty foods leads to obesity, diabetes and cancer."
The study results will appear this week in the online edition of Proceedings of the National Academy of Sciences

This finding dovetails with the reward theory of overeating, suggesting that animals including humans get more immediate endogenous drug-like reward from eating fats than carbohydrates or proteins, partially because fats supply more than twice as much energy per gram as carbohydrate or protein.

Piomelli apparently also serves as Director of the UCI School of Medicine’s Center for Drug Discovery & Development and hopes to find a pharmaceutical solution:

"The findings suggest it might be possible to curb this tendency by obstructing endocannabinoid activity – for example, by using drugs that “clog” cannabinoid receptors. Since these drugs wouldn’t need to enter the brain, they shouldn’t cause the central side effects — anxiety and depression — seen when endocannabinoid signaling is blocked in the brain, Piomelli noted."
So there you go, a pharmaceutical solution to the obesity problem.   Just throw a monkey wrench into the intricate and poorly understood symphony of neurochemicals.  No need to worry about side-effects, right?

How about teaching people to recreate the ancestral environment instead?  What did he say?  "Fats are scarce in nature."  By "nature" he means in the ancestral environment

Could this be why humans need only about 20-25 g of essential fats daily, compared to ~50-60 g of protein and at least 150 g of glucose?  Does it make sense that human macronutrient requirements would mirror the relative availability of nutrients in the ancestral environment and diet?

And are things really that different in the agricultural food supply?  I mean, although fat seems abundant in industrialized nations, does this reflect nature, or human intervention?  After all, agriculture is part of nature.  Does agriculture produce more fats, proteins, or carbohydrates?  If you look at the world at large, at the entire human food supply on the planet, is fat relatively abundant, or relatively scarce, although concentrated in certain locations?  How about protein?  Carbohydrate?

Why would evolution favor a system that offers an animal a higher immediate reward for eating fats than for eating protein or carbohydrate? 

Would this reward system be more advantageous in an environment where fats were easy to obtain, or in an environment where fats were hard to obtain?

In other words, would nature make it more highly rewarding to eat something available frequently, with little effort, or something available only infrequently and with great effort?

From another angle, which would this system help most:  an animal that had a continuous supply of fats, or one that had an intermittent supply of fats?