Zhaoping Li, MD, PhD, chief of the Division of Clinical Nutrition at UCLA Health, acknowledges the great potential of GLP-1 drugs. But she emphasizes they are just one of many options available to treat obesity and that success depends on an individualized approach.
Dr. Li, the Lynda and Stewart Resnick Endowed Chair in Human Nutrition and director of the UCLA Center for Human Nutrition, has extensive experience designing and leading clinical trials on obesity, metabolic disease and food-as-medicine interventions. Here, she offers expert insight into the promise and pitfalls of GLP-1s.
Q: Do GLP-1s fundamentally change the nutritional approach to obesity or are they a temporary fix?
Dr. Li: GLP-1s are an important addition to our obesity treatment toolkit. They help reduce appetite and support weight loss, but they are not a standalone solution. Lasting results require lifestyle change, including nutrition, activity and behavior modification. Without those components, GLP-1s are more likely to offer short-term benefit only.
Q: How do GLP-1s interact with nutrition, the microbiome and individual metabolism?
Dr. Li: GLP-1s do not affect everyone the same way. A person’s age, sex, microbiome, metabolism, nutritional baseline and functional status all influence how their body responds. Some patients are prone to losing lean body mass rather than fat. Others may experience vitamin and mineral deficiencies. We need individualized nutrition strategies to minimize risks and optimize results.
Q: Who benefits most from GLP-1s? And who might not?
Dr. Li: There is wide variation in response. Some patients achieve significant weight loss, while others plateau early or experience side effects that limit use. At UCLA, we take a team-based approach that combines nutrition, medical and behavioral expertise to find the right treatment for each patient. GLP-1s are one option among many.
Q: Why does a personalized nutrition plan matter when using GLP-1s?
Dr. Li: It is essential. Patients differ in how they process and store energy, build or lose muscle, and respond to changes in appetite or activity. If we rely on a one-size-fits-all approach, we risk harming patients by promoting muscle loss or triggering nutritional deficiencies. Tailoring treatment helps people lose fat while protecting muscle and function.
Q: Are we missing the chance to integrate GLP-1s with structured dietary care?
Dr. Li: Yes. Many patients are prescribed GLP-1s without support from a dietitian or nutrition team. As a result, they may not eat enough protein, miss key nutrients, or lose weight too quickly. Without structured nutrition care, weight loss may stall or reverse, and long-term success becomes less likely.
Q: What should we know about access and equity in GLP-1 research and outcomes?
Dr. Li: Most GLP-1 clinical trials are conducted in majority white, higher-income populations. Dietary support in these trials is minimal and not culturally tailored. That means we have limited data on how these drugs work in the real world for diverse patients, and we risk reinforcing disparities if access remains limited.
Q: What safety issues need more attention in the public conversation?
Dr. Li: Loss of lean body mass is a real concern, especially in older adults. Nutritional deficiencies can develop quickly if appetite is suppressed, and food intake drops. Some patients also report mood changes or symptoms of depression. These risks need to be discussed openly so patients and providers can make informed decisions.
Q: What’s the most urgent unanswered research question?
Dr. Li: We need to understand how to help patients lose weight while preserving muscle, maintaining nutritional health and supporting mental well-being. Current trials focus mostly on weight loss numbers, but real-world success depends on much more than the number on the scale.
Q: Are GLP-1s overrated?
Dr. Li: GLP-1s are often overhyped in public conversation. In clinical trials, results are carefully controlled. In the real world, outcomes tend to be more modest, and many patients regain weight after stopping the drug. These medications can help, but they must be part of a larger care strategy.
