Comparing energy expenditure data among individuals differing in body size and composition: statistical and physiological considerations

Acute and chronic diseases are frequently characterized by alterations in energy metabolism that influence nutritional requirements and clinical care. Knowledge of the effect of disease on daily energy expenditure and its components is fundamental to understanding the impact of the disease process on energy balance. To obtain this information, energy expenditure data are often compared between healthy and diseased individuals. This review focuses on the statistical and physiological issues related to comparing energy expenditure data among individuals who differ in body size and composition.