Limiting access to food in mice increases levels of the hormone, ghrelin, which may also increase motivation to exercise, according to a study published in the Journal of Endocrinology. The study suggests that a surge in levels of appetite-promoting hormone, ghrelin, after a period of fasting prompted mice to initiate voluntary exercise. These novel findings indicate that better diet control, for example limiting food intake to mealtimes or fasting intermittently, could help overweight people maintain a more effective exercise routine, lose weight and avoid debilitating complications such as diabetes and heart disease.

https://www.sciencedaily.com/releases/2019/10/191019154000.htm