Exercise is clearly part of a healthy fitness equation, but it also seems to play a role in steering us toward making healthier food choices, according to a study published in the American Journal of Clinical Nutrition (doi:10.3945/ajcn.113 .071381).
University of Birmingham (England) scientists asked 15 young, healthy men to jog gently on a treadmill for up to an hour. Afterwards, they were shown images of low-calorie, healthy foods and then fatty, less healthy fare as their brains underwent MRI scanning to monitor reward-centric activity levels. The experiment with food images was then repeated after an hour of relaxation instead of exercise. Results showed that neuron cells in regions of the brain that become more active when they sense a “reward” responded more to low-fat food images after exercise than when volunteers were sedentary.
“Exercise increases neural responses in reward-related regions of the brain in response to images of low-calorie foods and suppresses activation during the viewing of high-calorie foods,” concluded the authors in the study abstract. “These central responses are associated with exercise-induced changes in peripheral signals related to appetite-regulation and hydration status.”