ABSTRACT
Introduction From the therm al po in t o f v iew the b o d y can be considered as a heat engine. T hat is, it is a device w hich burns fuel in oxygen to release energy. T he fuel norm ally is in the fo rm o f carbohydrate , a lthough fat or even protein can be broken d ow n in to constituents for use as fuel in the absence o f carbohydrate. T he fuel is derived from ingested foodstuffs. T he oxygen, o f course is derived from the air th ro u g h the gas exchange process o f respiration. T he chem ical processes invo lved in the conversion o f carbohydrates and fat to energy and heat are collectively referred to as energy m etabolism .
