What is the mechanism of action of orlistat in the treatment of obesity?

Orlistat functions primarily by inhibiting the action of gastric and pancreatic lipases, which are enzymes essential for the digestion of dietary fats. When these enzymes are inhibited, the breakdown of triglycerides into free fatty acids and monoglycerides is disrupted, leading to reduced absorption of fats in the intestines. As a result, approximately 30% of dietary fat is not absorbed but instead is excreted in the stool. This reduction in fat absorption contributes to weight loss and is particularly effective when combined with a reduced-calorie diet.

This mechanism stands out among the options because, unlike methods that focus on increasing metabolism, suppressing appetite, or enhancing glucose utilization, the action of orlistat is specifically targeted at the mechanism of fat digestion and absorption in the gastrointestinal tract. This unique approach makes it a therapeutic option for obesity treatment, focusing on the type of macronutrient intake rather than other metabolic pathways.