Are gut peptides a new class of anorectic agents?

In the past 20 years, the mechanisms of the satiating effect of food that terminate a meal have been investigated intensively in rodents and in humans. This research has revealed that three peptides, cholecystokinin, pancreatic glucagon, and bombesin, released by ingested food from the gastrointestinal tract decrease meal size in a specific, dose-related manner without signs of acute toxicity or tolerance. In humans, the three peptides decrease meal size without decreasing the reported pleasure or satisfaction of the meal. Although their chemical structure and specific effect justify calling these peptides a new class of anorectic agents, not enough work has been done to evaluate their efficacy for weight loss in obese humans or their safety when administered for months.