Why do we get fat

Chapter 27: Meat or Vegetarian?This is a problem (1)
In 1919, cardiologist Blake Donaldson prescribed a meat-based diet for his obese patients, which he called a "cardiotonic."Even 90 years ago, the medical community knew that obesity was a major "potential" for heart attacks.Donaldson said he once visited the local natural history museum and asked the anthropologists at the museum what our prehistoric ancestors ate.They then told him that ancient humans ate "the fattest animal meat that could be killed," adding root vegetables and berries for a taste change.Donaldson then decided that meat should be "the essence of weight loss."His diet for obese people is: three times a day, eat about 200 grams of meat each time, with a little fruit and potatoes, to replace the "root vegetables and berries" of primitive people.

Donaldson has been using this prescription to treat obese patients.When he retired 40 years later, he had successfully cured 17000 obese people with weight problems.But here we should be serious in saying that he "claimed" to have cured so many people.After all, Donaldson was not ahead of his time, and his weight-loss diet wasn't entirely true.However, the reflections and debates he brought us continue to this day.That is, how much has our body evolved from hominids to the present to change our diet to the same extent?

From another perspective, once a particular food is included in the human diet, the longer the time, the better the genetic adaptation to it, the more beneficial it is, and the less harmful it may be.The longer we eat it, the more we become accustomed to it.Correspondingly, if a certain food is new to the history of human diet, or eaten in large quantities suddenly, it is likely that our genes will not have time to adapt to it, so it is easier for our body cause some damages.

In the 20s, the British epidemiologist Geoffrey Rose (Geoffrey Rose) clearly proposed a set of fundamental measures to prevent chronic diseases in his articles for the first time.The approach, Ross said, is to remove those "unnatural elements" while restoring "biological normalcy."From the perspective of genetics, it is to explore what conditions our genes can roughly adapt to, and to establish standardized dietary measures according to these conditions. Such a diet can be considered safe.Therefore, we should strongly recommend people to eat these foods and get health benefits from them.

For us, there is a troublesome question: what are the conditions that our genes are roughly adapted to, from a genetic point of view?In fact, the hypothesis put forward by Donaldson in 1919 can answer this question.The stable formation of human genes has a history of 250 million years.In this long history, our ancestors have been hunting and gathering for a living, and did not start to engage in agricultural production until 1.2 years ago.The first stone tools were born during the Stone Age, and the Stone Age occupies 99.5% of human history.Over 10 generations of humans have subsisted as hunters or gatherers.In contrast, there were only 600 generations in the agricultural period, and only 10 generations in the industrial period.

It is undisputed that the agricultural period, which accounted for only 0.5% of the most recent historical development of our species, had little impact on the shaping of our genes.What we need to focus on is the 250 million years before the agricultural period - what was the food we ate in the Paleolithic period.Unfortunately, we will never be able to answer this question accurately, after all, that era was long before human beings had written records.What we can do is to simulate the hunter-gatherer social model through the cooperative research of anthropologists and nutritionists, so as to get a glimpse of the living conditions of the Stone Age.

In 2000, researchers in the United States and Australia published a dietary analysis of 229 hunter-gatherer groups.These groups struggle to survive in today's world, but anthropologists have just been able to assess their diets.To date, this analysis remains the most comprehensive analysis of the diets of modern hunter-gatherers.We can "see" Paleo's eating patterns from the research, and we can also know whether a weight-loss diet that is low in carbohydrates and rich in protein is also good for our health.

First, from an ecological point of view, this diet is indeed feasible.The report said hunter-gatherers ate "significant amounts" of meat.In fact, 229 percent of these 20 primitive groups subsisted almost entirely on hunting or fishing.These groups get more than 85 percent of their daily calories from meat or fish, and some even 100 percent.This tells us that we can do just fine on a diet completely free of fruits, vegetables and grains, if not for a change.Fourteen percent of the hunter-gatherer groups got more than 14% of their calories from plants, and none of the groups were vegan.On average, hunter-gatherers consumed two-thirds of their calories from meat and one-third from plants.

Second, these groups adopted diets that were high in fat and protein.We've been told for the past 50 years to eat low-fat food, and we usually do.15% of our calories come from protein, 33% from fat, and over 50% from sugar.But the diet structure of these contemporary hunter-gatherer groups is completely different from the nutritional standards we are now promoting, and most of them are more consistent with their Paleolithic ancestors.

Compared with the diet we admire today, their diets were considerably higher in protein, at 19 to 35 percent of calories, and higher in fat, at 28 to 58 percent.Some groups even get more than 80 percent of their calories from fat.The high-fat diet is similar to the traditional eating habits of the Inuit. Before the trade with Europeans, the Inuit did not add sugar or flour to their diet.

People living in hunter-gatherer groups are used to giving priority to eating the fattest animals they can catch, giving priority to eating the fattest parts of these animals, including internal organs, tongues, bone marrow, etc., and they will also eat the body parts of animals "Almost all" fat.In other words, they preferred fatty meats and offal to the lean meats we buy in supermarkets or order in restaurants today.

Third, the diets of hunter-gatherers were low in carbohydrates by "normal Western standards"—only 22 to 40 percent of total energy on average.The most direct reason is that hunter-gatherers prefer to eat the meat they hunt.Another reason is that wild plant foods are relatively low in sugar compared to the flours and starches we like to eat now.All of the plant foods that these groups collected, such as seeds, nuts, roots, tubers, bulbs, leafy greens, and fruit, had a low glycemic index (GI) and a very slow rise in blood sugar.Correspondingly, the response rate of insulin is also very slow and reasonable.These hunter-gatherers not only consumed less sugar, but most of the sugar they digested was plant fiber, which was not easy to digest, digested slowly and satiated.Anthropologists tell us that the invention of cooking more likely began with making plant fibers more digestible, and then grilled meat.To be clear, these foods are not fattening.

What we can confirm from experimental reports is that hunter-gatherers relied on a diet quite different from that recommended by health authorities today.They avoid "healthy" carbohydrate-rich, easily digestible starchy foods such as corn, potatoes, rice, wheat, and legumes.

(End of this chapter)