Starvation response

Changes in metabolism that occur in response to a lack of food Starvation response in animals (including humans) is a set of adaptive biochemical and physiological changes, triggered by lack of food or extreme weight loss, in which the body seeks to conserve energy by reducing metabolic rate and/or non-resting energy expenditure to prolong survival and preserve body fat and lean mass. Equivalent or closely related terms include famine response, starvation mode, famine mode, starvation resistance, starvation tolerance, adapted starvation, adaptive thermogenesis, fat adaptation, and metabolic adaptation. In humans Ordinarily, the body responds to reduced energy intake by firstly exhausting the contents of the digestive tract along with glycogen reserves present in both muscle and liver cells through glycogenolysis. After prolonged periods of starvation, this store of glycogen runs out, and the body then starts burning fat reserves and consuming muscle and other tissues. It uses the proteins within muscle tissue as a fuel source, which results in loss of muscle mass. Magnitude and composition The magnitude and composition of the starvation response (metabolic adaptation) was estimated