Drugs like Wegovy and Zepbound — GLP-1 medications typically used to treat obesity — can lead to impressive weight loss.
But a new joint advisory from four major medical groups warns that without proper nutrition and lifestyle support, people may face muscle loss, weight regain, and high long-term costs once they take themselves off GLP-1 medications.
Experts from the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association and The Obesity Society contributed to the report, which noted that only about half of users continue taking their GLP-1 medication after one year and only about 15% remain on treatment after two years.
Many people stop taking GLP-1 medications due to side effects, cost or disappointing results — and when they do, they often regain weight, making long-term success depend on consistent use and a healthy diet, the report stated.
Boxes for the medications Wegovy and Zepbound are shown in California, on May 8, 2025.
Jonel Aleccia/AP
The report aims to guide both clinicians and patients on nutrition and lifestyle changes to improve long-term outcomes while taking a GLP-1.
“We really wanted to bring in four major societies together that focus on nutrition, lifestyle, [and] obesity and come with a consensus statement on how nutrition should be thought about when prescribing these drugs,” Dr. Dariush Mozaffarian, a cardiologist, director of the Food is Medicine Institute at Tufts University, and the report’s lead author, told ABC News.
Mozaffarian explained that for someone to achieve success on a GLP-1, they need to commit to comprehensive lifestyle changes.
“The FDA says these drugs are approved for use as an adjunct to lifestyle therapy,” he said. “In fact, they are prescribed the other way around with lifestyle therapy being the adjunct if being thought about at all. Doctors are not following either society guidelines or FDA guidelines if they are prescribing [GLP-1s] without lifestyle therapy.”
Before starting GLP-1 medications, the report recommended that patients work with their doctors to set goals that focus on overall health, not just weight loss. It’s also important to check for any stomach or bone issues that could lead to side effects like nausea, vomiting, or muscle and bone loss, the report stated.
“Registered dietitians can play really key roles in comprehensive obesity care by providing medical nutrition therapy to support GLP-1 therapy,” said Emily A. Callahan, registered dietitian nutritionist and director of policy strategy for the Food is Medicine Institute. “The evidence space is growing that shows when registered dietitians deliver medical nutrition therapy, it has been associated with improvements in body weight, waist circumference, blood pressure and glycemic control.”
People should usually start GLP-1 medications at the lowest dose and slowly increase as needed, the report said. Patients should also be aware that nausea is common when taking these drugs and this may trigger cravings for sugary, high-calorie comfort foods that work against weight loss. To stay on track, the report recommended eating small, frequent meals and focusing on minimally processed, nutrient-rich foods.
The report called for exercising special caution for anyone following an intermittent fasting diet or a low-carbohydrate “keto diet” that limits foods like breads, pastas and fruit to put the body into a state called ketosis, where it burns fat for fuel instead of carbs. These individuals might be especially vulnerable to gastrointestinal side effects, the report said.
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The report also advised people who may not be getting enough nutrients to consider taking supplements like vitamin D, calcium and multivitamins, while increasing protein intake by 50-100% from foods such as fish, eggs, nuts and seeds. This is especially important for those eating less while on GLP-1s, since lower food intake can make it harder to get all the nutrients the body needs.
The report also underscored the importance of maintaining muscle mass and bone density while losing weight. Since weight loss can also lead to muscle loss — especially in older adults — the report advised doing a full body strength training routine at least three times a week and getting 150 minutes of moderate cardio each week.
Focusing on nutrition, physical activity and other healthy lifestyle habits should give GLP-1 users a greater chance of achieving their goals, the report concluded.
“GLP-1s have the best chance of helping people achieve and sustain lasting weight reduction when they are paired with strong nutrition guidance and lifestyle support,” said Callahan.
Dr. Brendan Huang serves as the chief resident physician in adult neurology at Northwell Health and is also a member of the ABC News Medical Unit.