Weight Changes After Incretin-mimetics

The goal of this study is to identify people at risk of weight regain after stopping an injectable weight loss drug. The main question the investigators aim to answer is: Can weight regain be predicted by measuring circulating Agouti-related peptide, a small protein coming from the brain?

This study will enroll people who are taking an injectable weight loss drug, have lost weight with the help of this drug, and are required by their health insurance plan to discontinue treatment. Participants will first be screened for health conditions that would prevent them from entering the study. Once enrolled, participants will be asked to have the following testing while still on the injectable weight loss drug: body weight measurement, body composition (fat and lean mass), resting energy expenditure (calories burned), multiple blood draws after overnight fast and after drinking and nutritional shake urine collection, urine collection, measurement of heart rate, measurement of physical activity and sleep, questionnaires. Participants will then stop taking the injectable weight loss drug when the prescription runs out, and the same tests will be repeated 3 months later.