What happens when patients stop using GLP-1 medications for weight loss?

As GLP-1 use continues to proliferate in the treatment of obesity and as a weight management tool, new bodies of research reveal what happens when people stop using appetite suppressants like Ozempic and Mounjaro. While the studies focus on different aspects, one common outcome is weight gain after discontinuing GLP-1 injections. This, in turn, raises questions about whether following a healthy diet and engaging in physical activity is a better long-term approach to weight management.

Originally used strictly as a medical treatment for obesity and related illnesses, such as type 2 diabetes, GLP-1 use has proliferated outside of this category with sharp rises in use in several countries, including the US and UK, as the number of people taking up private prescriptions soars. This trend is also raising concerns over a possible lack of clinical oversight.

GLP-1 medication continues to gain traction, and not exclusively for those with chronic weight issues. It’s reshaping some aspects of the F&B landscape, including changes in consumer behavior in terms of purchasing decisions, as well as a specific interest in GLP-1-friendly food and drink products that align with weight loss goals. 

With a reduced appetite, consumers want to get more nutrition and functionality out of the smaller portions of food they eat, so packing in protein, fiber, and other essential nutrients is becoming increasingly important. 

However, health advocates continue to stress that GLP-1 injections are not a “magic fix” and should be used in conjunction with behavioral and lifestyle support, including nutrition and exercise, as part of a comprehensive approach to health. 

These recommendations come amid several new studies on GLP-1 use and its effects when it is stopped. 

Lack of nutritional support

New research from the University of Cambridge, UK, examines weight loss drugs like emaglutide and tirzepatide (available under brand names including Ozempic, Wegovy, and Mounjaro). These drugs mimic the naturally occurring hormone GLP-1, and are reportedly capable of reducing calorie intake by between 16% and 39%.

A systematic scoping review of existing studies, published in Obesity Reviews, found a lack of robust evidence surrounding nutritional advice and support, as well as the impact this has on factors such as calorie intake, body composition, protein adequacy, and patient experiences.

Dr. Marie Spreckley, from the Medical Research Council (MRC) Epidemiology Unit at the University of Cambridge, says: “Use of GLP-1 receptor agonist therapies has increased rapidly in a very short period of time, but the nutritional support available to people using these medications has not kept pace. Many people receive little or no structured guidance on diet quality, protein intake, or micronutrient adequacy while experiencing marked appetite suppression.”Use of GLP-1 receptor agonist therapies has increased rapidly in a very short period of time as more people are treated for obesity and weight loss.

“If nutritional care is not integrated alongside treatment, there’s a risk of replacing one set of health problems with another, through preventable nutritional deficiencies and largely avoidable loss of muscle mass. This represents a missed opportunity to support long-term health alongside weight loss.”

Dr. Cara Ruggiero, co-author from the MRC Epidemiology Unit at the University of Cambridge, notes that a clear gap remains in structured nutritional guidance. However, well-established post-bariatric nutrition principles can be drawn upon. 

These principles emphasize the importance of prioritizing nutrient-dense foods, including high-quality protein, ideally distributed evenly across meals, to help preserve lean mass during periods of reduced appetite and rapid weight loss.

Regaining weight

Another study from the Nuffield Department of Primary Care Health Sciences, University of Oxford, UK, and published in BMJ, finds that people tend to regain weight rapidly after stopping weight-loss drugs. Most people involved in the study regained all the weight they had lost within two years of stopping GLP-1 use. 

While there is no doubt they work to control the “food noise” often associated with over-eating, kill cravings for ultra-processed foods, and increase feelings of fullness, stopping them can lead to weight gain. 

The Oxford study notes that this is particularly poignant for individuals who are not adequately supported in terms of their nutrition and long-term health after discontinuing GLP-1s. 

Moreover, it raises questions about whether a healthy diet is a more effective long-term weight management strategy than turning to GLP-1 drugs, which users have to eventually stop taking. 

Muscle mass

Evidence suggests that lean body mass, including muscle, can account for up to 40% of the total weight lost during treatment. This issue is leading to a wealth of high-protein GLP-1 companion products on the market to help people regain muscle mass that may have been lost during GLP-1 use. 

Researchers analyzed 37 studies comprising 9,341 adults, in which weight increased by an average of 0.4 kg (0.9 pounds) per month after the cessation of weight management drugs. Researchers estimate that people typically return to their starting weight within one to two years.Some health experts believe physical activity and obesity prevention is a better strategy for weight management.

Weight regain after stopping medication was faster than after ending behavioral weight loss programs, such as diet and exercise support by approximately 0.3 kg (0.7 pounds) per month — independent of how much weight was initially lost. 

“These medicines are transforming obesity treatment and can achieve important weight loss. However, our analysis shows that people tend to regain weight rapidly after stopping – faster than we see with behavioral programs,” says lead author Dr. Sam West, postdoctoral researcher at the Nuffield Department of Primary Care Health Sciences. 

“This isn’t a failing of the medicines. It reflects the nature of obesity as a chronic, relapsing condition. It sounds like a cautionary note for short-term use without a more comprehensive approach to weight management.” 

Long-term approach to weight management

The study also found that cardiometabolic markers, including HbA1c, fasting glucose, blood pressure, cholesterol, and triglycerides, improved during GLP-1 treatment but are estimated to return to baseline levels within approximately 1.4 years after medicines are stopped.

Professor Susan Jebb, joint senior author, adds: “Obesity is a chronic, relapsing condition, not a short-term problem with a quick fix. When people lose weight through changes to their diet and activity, they’re practicing the skills that help maintain that loss. It may be that with medication, the weight comes off without necessarily developing those skills.”

“These findings underscore the need for a more holistic and long-term approach to weight management, and increased emphasis on the importance of primary prevention of weight gain.”

“For practitioners prescribing, patients receiving, and people choosing to purchase these medications privately, it’s important to understand the risks of rapid weight regain if treatment ceases — and the value of wraparound behavioral support.”