Pharmaceutical companies and scientists have been working for decades to find a magic pill to make us feel more satisfied and eat less. Fortunately, researchers at the University of Campinas in Brazil may have found a link to making us feel full—without the use of drugs.
Some of our eating habits—particularly if they involve a lot of fatty foods like fries and pizza—may cause us to lose the ability to know when we're full. Some research suggests that eating excessive amount of fat creates failures in the brain's signals that control satiety in the hypothalamus (the area of the brain that manages hunger). These failures can lead to uncontrollable food intake and, thus, obesity. Brazilian researchers, led by Jose Barreto C. Carvalheira, set out to determine if exercising obese rodents could restore satiety and decreased food intake.
The set-up: The researchers studied a group of rats—half of which were of normal weight, while the other half were considered obese. Both groups were put under physical exercises such as swimming and running on a treadmill. Their eating habits were also closely monitored before and after the exercise routines.
The results: The obese rats that used to eat a lot before they were subjected to regular exercise started eating less after engaging in physical activity.
"In obese animals, exercise increased protein levels in the hypothalamus, and these molecules were crucial for increasing the sensitivity of the most important hormones, insulin and leptin, which control appetite," Carvalheira explained.
Obviously, physical activity increases energy expenditure and burns calories, but this study found that exercise also adjusts the signals of satiety and reduces food intake.
This chemical change suggests that physical activity "could help to reorganize the set point of nutritional balance and, therefore, aid in counteracting the energy imbalance induced by overnutrition-related obesity," Carvalheira noted in the study.
However, the study did not find any concrete proof to link the results with weight loss.