If you just overindulged in high calorie foods during the holidays, there is an unexpected way to defend yourself, at least next time: resisting the "sins" of gluttony through physical activity.
It is what researchers at the Department of Psychiatry at Harvard Medical School, Boston, found in a study published in Neuroreport last 4th of December.
This means that the brain of active people tends to be less "reactive" in front of "tempting foods".
Therefore exercise not only burns the extra calories, but can reduce our preferences for unhealthy high-calorie foods.
But there is some more evidence: another recent research published in the American Journal of Clinical Nutrition studied the effects of high-intensity exercise on neural responses to images of food. Fifteen lean healthy men completed two 60-min trials—exercise (running at ∼70% maximum aerobic capacity) and a resting control trial —in a counterbalanced order. After each trial, a functional magnetic resonance imaging assessment was completed in which images of high- and low-calorie foods were viewed.
The study found that exercise significantly suppressed subjective appetite responses while increasing thirst and core-body temperature. Furthermore, exercise significantly suppressed ghrelin (the "hunger" hormone) concentrations and significantly enhanced peptide YY (a hormone made in the small intestine; it helps to reduce appetite and limit food intake) release.
Bottom line: physical exercise not only has many health benefits, including improved cardiovascular fitness, lean muscle development, increased metabolism, and weight loss, as well as positive effects on brain functioning and cognition; regular exercise also affects the responsiveness of reward regions of the brain to food stimuli and so can break the addiction to unhealthy foods.