Mechanisms of metabolic fuel selection: modeling human metabolism and body-weight change.

Casual observation of any magazine rack or browsing the diet section of any bookshop provides convincing evidence that weight loss is of great interest to the U.S. population. Americans spend more than US$30 billion/year on weight-loss products, and the health cost of obesity was recently estimated to be as high as US$147 billion/year. Understanding the development of obesity and how excess weight can be lost requires knowledge of the physiological mechanisms by which the body uses food to provide fuel for metabolism and how the body copes with imbalances between fuel delivery and utilization.