How do diet drugs such as liraglutide and phentermine-topiramate help people lose weight?

• A. They suppress appetite and increase feelings of fullness, leading to reduced calorie intake.
• B. They slow down metabolic rate to conserve energy.
• C. They increase the absorption of nutrients from the digestive tract.
• D. They directly break down fat cells in the body without affecting appetite.

Answer: (A)

Verified step by step guidance

1. Understand the mechanism of action for each drug mentioned: Liraglutide is a GLP-1 receptor agonist, which mimics the action of the hormone glucagon-like peptide-1 to regulate appetite and increase feelings of fullness. Phentermine-topiramate is a combination drug where phentermine suppresses appetite and topiramate enhances satiety.
2. Analyze the physiological effects of appetite suppression and increased feelings of fullness: These effects lead to reduced calorie intake, which is a key factor in weight loss.
3. Evaluate the incorrect options: Slowing down metabolic rate would conserve energy, which is counterproductive for weight loss. Increasing nutrient absorption would not directly lead to weight loss, and breaking down fat cells directly without affecting appetite is not the mechanism of these drugs.
4. Relate the correct mechanism to the desired outcome: By suppressing appetite and increasing satiety, these drugs help individuals consume fewer calories, creating a caloric deficit necessary for weight loss.
5. Conclude that the correct answer is: 'They suppress appetite and increase feelings of fullness, leading to reduced calorie intake,' as this aligns with the known mechanisms of liraglutide and phentermine-topiramate.