Factors influencing brown fat and the capacity for diet-induced thermogenesis.

The experimental evidence for the existence and importance of diet-induced thermogenesis in laboratory rodents is reviewed, and the influence of various factors (e.g. age, genetic background, diet composition and early environment) discussed. The physiological, pharmacological and biochemical data implicating sympathetic activation of brown fat as the principal source of diet-induced thermogenesis are described, and followed by a review of the neurohumoral influences (e.g. dopamine, histamine, insulin, thyroid and adrenal steroids) on thermogenesis and brown fat activity. The possible relevance of these animal studies to human metabolism is discussed briefly.