Carbohydrates and protein don't seem to have any effect on weight
According to a new study, fat consumption is the only cause of weight gain. Researchers claim that carbohydrate and protein intake has no effect on body weight.
In their current study, scientists from the University of Aberdeen and the Chinese Academy of Sciences found that fat consumption appears to be the only cause of possible weight gain. The doctors published the results of their study in the English-language journal "Cell Metabolism".
The study was carried out on mice
For their study, the experts examined a number of different types of diet in mice that have a similar physiology and metabolism to humans. The study included a total of 30 types of diet, the fat, carbohydrate and protein content of which varied. Each of the test mice was fed the allocated diet for a period of three months, which is equivalent to nine years in humans. In total, more than 100,000 body weight changes were measured during the study and the body fat of the animals was measured using a so-called micro-MRI device.
The combination of sugar and fat had no greater impact than fat alone
The result of this extensive study was clear. When the mice consumed more fat in their diet, the mice gained weight and developed overweight or obesity, said study author Professor John Speakman of the University of Aberdeen. Ingested carbohydrates, which contain up to 30 percent of the calories, had no effect on body weight. The combination of sugar and fat had no greater impact than fat alone, the expert added.
Fat stimulates the brain to absorb more
There was also no evidence that a low protein content (up to 5 percent) stimulated higher protein intake. In contrast, fat in the food stimulated the so-called reward center in the brain to increase its intake. It is difficult to conduct similar studies on people because it is difficult to control exactly what the participants consume for long enough, says Professor Speakman.
Study provides evidence of dietary effects
A clear limitation of this study is that it is based on mice rather than humans, the expert says. However, mice have many similarities to humans in their physiology and metabolism. Scientists suspect that studies that control people's diets in the same way for such a long time will never be carried out. The evidence provided by the current study is a good indication of the effects of different types of nutrition on humans, the researchers add. (as)