The effect of thermogenesis due to carbohydrate depends upon the metabolic utilisation of the nutrient. With the glucose clamp technique, when infusing glucose and insulin simultaneously, one can study glucose metabolism under steady states glucose and insulin plasma levels. The amount of glucose needed to maintain euglycemia can be monitored. The increment of energy expenditure is continuously measured by open circuit indirect calorimetry. The combined technique of glucose clamp with continuous indirect calorimetry allows to determine the rate of glucose storage. The experimental value for glucose-induced thermogenesis measured over three hours following glucose ingestion in young adults is around 12 to 15% of the energy content of the glucose load. The results support the concept of two components in the thermogenic response to glucose infusion: an "obligatory thermogenesis" which accounts for the energy costs of storing the nutrient and a "facultative thermogenesis" which is an energy dissipative process.