A fundamental and unresolved issue in obesity research is what foods are most likely to cause obesity. The reasons given by experts vary, such as foods that contain fat or sugar or foods that lack protein, as they may cause us to eat too much without knowing it. For any obesity culprit, a lot of trivial rebuttal evidence can be gathered, but there are few long-term and large-scale experimental studies on dietary habits. It is neither ethical nor realistic for a healthy subject to overeating a certain food for a long time until obesity.
However, it is possible to perform such an experiment on mice. In a diet study published this summer in Cell Metabolism, researchers randomly assigned one of 29 different diets to hundreds of adult male mice (scientists hope to include them in later experiments) Female mice). Some foods provide up to 80% calories in the form of saturated and unsaturated fats, while carbohydrates are rare; others are low in fat, mostly composed of refined carbohydrates mainly from grains and corn syrup, although some versions The carbohydrates come from sugar. Another diet is characterized by a very high or very low percentage of protein. These mice maintained the same diet for three months—estimated to be about nine years of humanity—while allowing them to eat and move around in cages. The researchers then measured the body weight and body composition of the mice and examined whether there was evidence of altered brain activity in their brain tissue.
Only some mice become obese - almost all high fat diets. These mice also showed signs of altered genetic activity in brain regions associated with treatment rewards; apparently, fat foods made them happy. Other diets, including those that are rich in sugar, did not result in significant weight gain or altered gene expression in the same manner. Even an ultra-high fat diet with more than 60% fat does not significantly increase body weight, and mice in this diet consume less food than other similar foods, probably because they simply can't eat so much fat. These findings also appeared in subsequent experiments with four other murine species. Male mice on a relatively high-fat diet became obese, while others did not.
John Speakman, a professor at the Chinese Academy of Sciences in Beijing and Aberdeen University in Scotland, said: "It looks like if you are a mouse, eat a high-fat diet, and not extremely high fat. If you do, it will lead to weight gain.” Spicman and his co-authors believe that the fat-containing diet stimulates and changes certain areas of the brain, causing the mice to want to eat fat-containing foods so much that they are reminded that they have taken Enter other body signals of sufficient energy.
The focus of the study was on weight gain rather than reduction, and the subjects were apparently mice, not humans. But the result is suggestive. Sugar does not make mice fat, and there is no protein. Only fat makes them fat.