The study, published in the British Medical Journal (BMJ), begins with the scientific hypothesis that many people find their weight after a diet, partly because the metabolism slows down and the body adjusts to the so-called "natural weight" that causes fewer calories in their everyday lives, stores them.
The study examined the weight of 164 participants who were exposed to a controlled diet for 20 weeks. During this time, measurement of insulin secretion, metabolic hormones and total energy expenditure, ie calories burned, was also measured.
"This analysis is the largest dietary study to prove the" carbohydrate and insulin model "and provides a new way to treat obesity treatment," said lead researcher David Ludwig.
According to the model, "processed carbohydrates that flood low-fat diets increase insulin levels and therefore fat cells store more calories," explains Ludwig.
With fewer calories available for the rest of the body, hunger is increasing and metabolism slows down, leading to weight gain, the investigator concludes.
During the study, the participants were divided into three groups and received diets with different amounts of carbohydrates, so that scientists could compare energy consumption during calorie burning.
The results showed that total energy expenditure was significantly higher in low carbohydrate diet as participants consumed about 250 calories more per day than those who followed the diet with the highest carbohydrate intake (potatoes, rice, pasta, for example).
"This would translate into a weight loss of about 20 kilos after three years," says researcher Cara Ebbeling, the Spanish news agency Efe reported.
In addition, according to the study, the difference in calorie loss between rich and low-carbohydrate diet was much higher in people with high levels of insulin secretion, with an average of 400 calories burned per day.