Energy Expenditure
Weight-loss can be produced by increasing energy expenditure eg by increasing metabolic rate as shown by clinical studies with the uncoupling agent, dinitrophenol. This compound was used in the USA as a weight-loss agent in the 1930s before it was withdrawn when it was found to produce serious side-effects including increased body temperature and fatal hyperthermia. The observation that weight-loss can be produced by increasing energy expenditure, suggests that the effects of acute and chronic administration of potential antiobesity agents on metabolic rate should always be investigated. This can be measured in laboratory animals using closed circuit indirect calorimetry.
