Abstract
In the past decade, the antiobesity, antidiabetic and nutrient partitioning activities of β‐agonists have been extensively studied. The data generated from these compounds in experimental and farm animals have convincingly proved that body fat content and body weight can be modified to some degree by a metabolic agent without decreasing food consumption. Marginal antiobesity and antidiabetic activities in humans have been demonstrated with a few mixed β‐agonists under certain conditions, but their utility is limited by side effects. The concept of a β3‐receptor rose from the study of these compounds and has been verified by the cloning and expression of this receptor from several species. Rat β3‐selective agonists have so far shown no antiobesity efficacy in humans. The resolution of several issues is critical for the discovery and development of efficacious antiobesity and antidiabetic agents with minimum side effects. Ultimately, the further investigation of these β‐agonists and β‐receptors should lead to a better understanding of the relationship between energy metabolism and feeding behavior.