It’s one of life’s greatest injustices: Some people eat their fill without gaining weight, while others must control every food they put in their mouth to maintain a healthy weight. Why does this happen? According to Kathleen Melanson, professor of nutrition and food sciences at the University of Rhode Island (United States), the answer could be found in the genetic, nutritional and even behavioral factors of each person.
Also, the most important factor is not related to body type or metabolism, but to perception. According to Professor Melanson, people who seem to eat without gaining weight don’t actually eat much more than we do. For example, if a friend or family member eats ice cream every day, they may compensate by eating less at another meal or by eating less for the rest of the day. So if these people’s calories are counted, they may not eat as much as you think.
Physical activity also makes a difference, as some people walk daily or have an active job. This movement can speed up your body’s metabolism or increase the amount of energy your body expends during the day. Likewise, according to Inés Barroso, a researcher at the University of Cambridge (England), there is little scientific evidence to suggest that, without exercising, some people burn more calories than others.
On the other hand, genetics can influence a person’s tendency to lose or gain weight. According to a study published in PLOS Genetics, scientists have recognized more than 250 DNA regions that are linked to obesity. To carry out the research, the scientists compared healthy people (with a normal body mass index) with people who were severely obese. In this way, the researchers were able to conclude that the lean participants had fewer genes associated with obesity.
However, genes alone cannot determine a person’s weight. In fact, according to researcher Barroso, there are also people who have genes associated with obesity but are not obese. For this reason, the answer is quite complex, since our tendency to gain or lose weight is not completely under our control.
