Studies have shown that people who lose weight and not gain weight again usually watch what they eat, while those that recovers the lost kilos less meticulous. A new study, though small, suggests that this involves differences in the brain.
When shown pictures of food to people who had lost weight and had not returned to gain weight for years, they were more likely to activate brain areas associated with behavioral control, compared with obese participants and normal weight .
Our findings shed some light on the biological factors that may contribute to not to gain weight, said lead study author, Jeanne Mc Caffery,Miriam Hospital. They also provide a fascinating complement to previous behavioral studies that suggest that people who maintained a weight loss long term strictly monitors their food intake and exhibits restraint in their food choices.
The research, funded by the National Institutes of Health, is explained in detail in the American Journal of Clinical Nutrition.
The behavioral program participants lost weight reduction averaging between 8 and 10 percent of their weight during the first six months of treatment and after one year will not increase by approximately two-thirds the weight down, explain Mc Caffery and colleagues. However, despite intensive efforts, the weight recovery appears to continue over several years, since the majority of patient’s returns to its baseline weight after five years.
A separate study earlier this year found that when people choose to eat healthily, for example, eating vegetables instead of a sweet use a small region in their brains that is not used by those who indulge in eating what want. It is thought that this brain area is associated with willpower, scientists say.
In the new study involved three groups of volunteers- 18 people of normal weight, 16 obese people and 17 people who had fallen at least 13 kilos and the weight did not recover for at least three years.
After fasting for 4 hours to ensure that participants were hungry, they were shown pictures of food items, including low-calorie food, foods high in calories, and objects that were not food but they had to have a visual complexity, texture and color similar to these.
Their reactions were documented by magnetic resonance imaging.
The members of the group had managed not to gain weight when looking at pictures of food, showed strong signals in the left superior frontal region and right middle temporal region of the brain-a pattern consistent with greater inhibitory control in response to food images and greater visual attention to food courts, the researchers said on Tuesday September 15.
It is possible that these brain responses may lead to preventive or corrective behaviors-particularly greater regulation of food consumption-that promote weight control in the long term, said McCaughey, who is also an assistant professor of psychiatry and human behavior in the Warren Alpert Medical School at Brown University. However, future research is needed to determine whether these responses are inherent to an individual or if they can be changed.
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