What is the new theory of obesity that carbohydrates and lipids are not a direct cause of obesity?



Past studies have shown that `` high protein meals such as meat and dairy products increase the risk of heart disease ' ' and `` metabodies dramatically improve when sugar is withheld '', causing obesity It's becoming common sense that is taking too much carbohydrate and fat. However, nutritionist Kevin Hall argues that “carbohydrates and lipids are not a direct cause of obesity” and explains “the true cause of obesity”.

Ultra-Processed Diets Cause Excess Calorie Intake and Weight Gain: An Inpatient Randomized Controlled Trial of Ad Libitum Food Intake: Cell Metabolism

A New Theory of Obesity-Scientific American

Kevin Hall, who is studying metabolism and nutrition at the National Institutes of Health in the United States, thinks that it is the cause of obesity in modern people, through multiple processing processes such as frying, heating and molding Super-processed food mass-produced.


Oleg Magni

In fact, Mr. Hall thought that certain nutrients such as carbohydrates were the cause of obesity until he confirmed it himself. Mr. Hall said, “It is a known matter that the amount of insulin increased by carbohydrate intake and that the amount of fat stored increases if a lot of insulin is secreted, so the theory that certain nutrients are the cause of obesity is certain. Is credible. ” In order to prove this idea, Mr. Hall conducted an experiment in obese people with dietary restrictions that consumed less carbohydrates. In addition, the subjects in the control group were given a diet that did not restrict carbohydrates and kept only calories.

Hall, who thought that carbohydrates were the cause of obesity, saw that people with limited carbohydrates could lose weight faster. However, the result of this experiment is unexpectedly 'no significant change in fat loss with or without carbohydrate restriction'. Not only that, but those who were restricted in carbohydrates even had a slightly slower tendency to lose fat.

Hall, who was thinking about the results of this experiment, paid attention to the bias of nutrients in the diet that human beings had eaten so far. For example, Japanese food, mainly rice food, is “high carbohydrate, low fat”, but Japan is one of the countries with very little obesity among developed countries. Inuit people, who are mainly meat such as fur seals and walruses, have a typical “high-fat, low-carbohydrate” diet, but Inuit that continues traditional diets is still healthy. From this relationship between traditional diet and obesity, Hall arrived at the hypothesis, “It is not a bias in specific nutrients, but a change in diet that humans have recently experienced is the cause of obesity.”


Charles Haynes

What Hall considers as “meal change” is the emergence of super-processed foods. Until the end of the 19th century, most Americans lived in rural areas and ate fresh food and lightly cooked dishes. However, many Americans in recent years live in urban areas and eat processed foods mass-produced in factories every day. As a result, the United States in the 21st century has reigned as the first place in a country with a large obese population .

Therefore, Hall et al. Conducted an experiment with 40 adults in order to examine the effects of super-processed foods, which have been increasing rapidly in recent years, on the human body. The experiment is to divide the subjects into groups of 20 people and give them a general meal and a super-processed food meal. Two weeks later, the group was changed, and the same two weeks were spent.

Examples of super-processed foods given to subjects in the experiment include canned ravioli , hot dogs, processed cheese topped burgers, white bread, margarine, packaged cookies, artificial sweetened beverages, and spam . On the other hand, general foods such as roast beef, pilaf, pasta and granular pasta, couscous , nuts, vegetable omelet fried in oil, hashed potatoes using butter, yogurt that is not low-fat, are not super-processed foods. A menu that was not considered healthy was chosen.

by Prostock-studio

As a result of these experiments, subjects were said to be able to eat as much as they want to be satisfied in either group, but on average only a few hundred calories per day only when they were in the super-processed food group Was also taking extra. In just two weeks while eating super-processed foods, the body weight increased by 2 pounds (about 1 kg). Hall positions this experiment as `` proof of concept '' to the last, and there are few samples to determine that `` super-processed food is the direct cause of obesity '', and a control experiment when super-processed food is reduced I admit that there is no.

Still, Barry M. Popkin, Professor of Nutrition at the University of North Carolina at Chapel Hill, “Hall ’s experiments are very important.“ The people in front of super-processed foods eat too much. It was the first experiment that proved that it would be '' and said that it was highly appreciated as an experiment that revealed that carbohydrates and lipids are not likely to be a direct cause of obesity.

Than fried egg a person is made with real eggs, the reason why would prefer towards the omelet made with substitute egg, Dana Small, who is a psychiatry professor at Yale University, 'the brain and the gut is the second brain in I have a secret. According to a study conducted by Small in the past, detecting the color and odor of food that indicates high calories can activate the striatal body related to decision-making in the brain. In addition, the intestines are connected to the brain via the vagus nerve and send information such as the calories of what you eat to the brain.

However, if you take sweet artificial sweeteners without calories, a discrepancy will occur between the calories felt by the brain and the calories actually consumed by the intestines. In addition, foods that contain sugar and fat at the same time are rare in nature, but many processed foods contain carbohydrates such as sugar and fat at the same time. In this way, Mr. Small speculated that the confusion between the brain and intestines caused by processed foods and the bias of nutrients that human beings had never experienced before created the illusion that `` it is still not enough to eat '', leading to overeating. It is.

You can read more about Dana Small's research by reading the following article.

The combination of fat and carbohydrate attracts humans because it stimulates the brain's reward system-GIGAZINE

by Eugene Peretz

On the other hand, there are some skeptical nutritionists who view super-processed foods as the cause of obesity. Rick Matt, a professor of nutrition at Purdue University and the next president of the American Nutrition Society, said, “In the experiment, the subjects ate only processed food, but in the real world there are few people who eat only processed food. 'It's not limited to Mr. Hall's experimentation, but trying to apply extreme experimental results to people who live normally is a serious problem,' he said, saying that super-processed foods are the cause of obesity. He indicated that it was premature.

Hall said, “We have revealed the link between super-processed foods and overeating, but we still do n’t know the mechanism. There is a theory that additives and fragrances are the cause, and micronutrient deficiencies. There is also a view that this is the cause. '

“I am neither a savior nor a healthy diet evangelist who improves the eating habits of modern people,” says Hall, who is also the father of a 4-year-old who loves chicken nuggets and pizza. We can review the diet, and such movements should be more powerful than government measures such as taxing sweets and fats, ”he said. And thought that it is necessary to face health.

in Science,   Junk Food, Posted by log1l_ks