A new study revealed that yoyo-dieting, or the repeated cycle of weight loss and gain, may only lead to more substantial weight gain when the diet stop.

The study, published in the journal Evolution, Medicine and Public Health, showed that repeated dieting could be interpreted by the brain as short famines. Due to this, the brain urges the body to store more fat for future "shortages". This make repeated dieters to gain more weight compared to those who never diet.

"Our simple model shows that weight gain does not mean that people's physiology is malfunctioning or that they are being overwhelmed by unnaturally sweet tastes," explained Professor John McNamara, of the University of Bristol's School of Mathematics, in a press release. "The brain could be functioning perfectly, but uncertainty about the food supply triggers the evolved response to gain weight."

For the study, the researchers analyzed mathematical models of animals, like birds. These animals know whether food is currently abundant or limited. However, they have no idea when things will go from abundant to scarce. Due to this, birds must learn about the changeability before deciding how fat to be.

By observing how the animals responded to the risk of food storage, the researchers were able to understand why people who were under yo-yo dieting were more likely to be unsuccessful in losing weight. The researchers found that if the food supply is limited, as it is while dieting, birds and other animals tends to gain excess weight between shortages.

Because the brain interprets diets as some kind of food shortages, it urges the body to eat more when the diet stops. This suggests that the average weight gain of people on diet will be much greater than those who are not.

Furthermore, the brain will continue to urge the body to eat as the diet goes on, and this urge is less likely to be fulfilled because the brain is very much convinced that famines are likely to occur.

With their findings, the researchers recommended continues eating only slight less than usual during meals if they want to steadily loss weight. Exercise can also be a great help for people planning to lose weight in a healthy way.