Obesity is a global health epidemic that requires effective intervention strategies to avoid serious complications such as heart disease and diabetes. Regular exercise and limiting food are the two main cost-effective strategies to prevent and treat obesity. However the condition is often associated with a sedentary lifestyle and bad eating habits, such as snacking and binge eating. Consequently, adhering to a regular exercise regime can be difficult due to an inability to exercise for a prolonged period or a lack of motivation.

   Ghrelin, often referred to as the 'hunger hormone', that stimulates appetite through actions on the brain reward circuitry that increase motivation to eat. In a study conducted by Dr Yuji Tajiri and colleagues from Kurume University School of Medicine in Japan, investigated the relationship between exercise and ghrelin levels in mice. Food intake and wheel-running activity were compared in mice given free access to food and those fed only twice a day for a limited time. Although both groups ate a similar amount of food, the restricted mice ran significantly more. Mice genetically altered to have no ghrelin and on the restricted feeding diet ran less than the mice given free access, however, this could be reversed by administering ghrelin. Furthermore, mice given free access to food and given ghrelin also ran significantly more. These findings suggest that ghrelin may play an important role in the motivation for both feeding and exercise, in response to restricted eating plans

   According to the study published in the Journal of Endocrinology, 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 instance limiting food intake to mealtimes or fasting intermittently, could help overweight people maintain a more effective exercise routine, lose weight and avoid enervating complications such as diabetes and heart disease.