Why Does The Weight Come Back?
Author: Dr. Stephen Chaney
It is no secret that obesity has become an epidemic in this country. According to the CDC:
- The prevalence of obesity topped 40% in 2023.
-
- This represents a 3-fold increase over the past 60 years. [Note: Genetics doesn’t change that fast. This is a lifestyle disease.]
-
- Severe obesity has increased by 26% in just the last 9 years!
And obesity is deadly:
- It significantly increases the risk of type 2 diabetes, heart disease, high blood pressure, stroke, and several types of cancer.
- Severe obesity reduces life expectancy by 10-14 years!
It is no wonder that GLP-1 drugs have been hailed as a medical miracle.
- Participants in clinical trials of GLP-1 drugs lose 15-20% of their body within 15-18 months.
- Because GLP-1 drugs affect appetite, they don’t require participants to make any hard lifestyle changes [Hint: This is part of the problem.]
But studies show that most people stay on GLP-1 drugs for 12 months or less.
- In some cases, that is because minor side effects (nausea, diarrhea, constipation, and stomach pain) become too much of an annoyance over time.
- In other cases, the cost of GLP-1 drugs becomes too much of a burden over time.
- And weight loss often plateaus at around 12 months, reducing the incentive to stay on the drug.
It is probably a good thing that most people don’t stay on GLP-1 drugs long term because the risk of serious side effects (severe muscle loss, depression, suicidal thoughts) is cumulative. Those risks increase with long-term drug usage.
But what happens when someone discontinues a GLP-1 drug. Does the weight stay off, or does it come roaring back. In short, are GLP-1 drugs just another “yo-yo” diet fad?
In this article, I will address four questions:
#1: Are GLP-1 drugs just a temporary fix?
#2: Why does the weight come back?
#3: Would supplementation make a difference?
#4: What does this mean for you?
I will answer the first question by reviewing a recently published study. For questions 2 and 3 I will refer to studies I reviewed in previous issues of “Health Tips From the Professor”. Question 4 will represent my best advice to anyone who wants to lose significant weight and keep it off.
Are GLP-1 Drugs A Temporary Fix?
This study (S West et al, The British Medical Journal, 392:e085304, 2026) was a systematic review of 37 studies with 9,341 participants that looked at weight regain following weight loss with GLP-1 and similar drugs. The average length of weight-loss treatment in these studies was 39 (11-176) weeks followed by an average follow-up period of 32 (4-104) weeks.
The data were compared with data obtained from a previous study by the same authors of weight regain following behavioral (diet and exercise) change weight management programs.
What the authors found was:
- Weight regain following GLP-1-aided weight loss was almost a pound per month, which is 4 times faster than weight regain following weight loss for patients on behavioral management programs.
-
- Based on these numbers, weight was projected to return to the starting point within 1.5 years for the GLP-1-aided weight loss compared to 3.9 years following behavioral change programs.
- Markers of disease risk (hemoglobin A1c, fasting glucose, blood pressure, total cholesterol, and triglycerides) were projected to return to the starting level within 1.4 years for GLP-1-aided weight loss compared to 5 years following behavioral change programs.
- Weight regain was faster following GLP-1-aided weight loss than following behavioral modification, independent of the extent of initial weight loss.
The authors concluded, “This review found that cessation of WMM (weight management medications) is followed by rapid regain and reversal of beneficial effects on cardiovascular markers. Regain after WMM was faster than after BWMP (behavioral weight management programs). These findings suggest caution in…use of these drugs without a more comprehensive approach to weight management.”
The authors went on to say, “This evidence suggests that despite their success in achieving initial weight loss, these drugs alone may not be sufficient for long term weight control.”
Why Does The Weight Come Back?
I addressed this in a previous issue of “Health Tips From the Professor”. Here is an excerpt from that article:
The miracle of GLP-1 drugs is that they suppress appetite, which makes it much easier to lose weight.
- Snacks are no longer appealing.
- Large portion sizes leave you feeling bloated.
- It’s easy to skip meals because you just aren’t hungry.
You no longer have to struggle to eat less. It just comes naturally. But this miracle is also a snare.
Because GLP-1 is a drug, not a diet plan, it’s dispensed like any other drug.
- Your doctor gives you a GLP-1 prescription. If you are lucky, they may give you a “one-size-fits-all” handout on how to lose weight while you are using it. For example, in a recent study:
-
- Only 20% of patients were referred by their doctor to a dietitian. The other 80% received little or no information on how to change their diet and lifestyle.
- When you pick up the drug from the pharmacy, you get a package insert listing the side effects but no information on how to change your diet.
- And GLP-1 drugs are increasingly sold online where you are given even less information about diet and lifestyle change.
The results are predictable:
A recent study (S Hrisakeva et al, Journal of Marketing Research, December 18, 2025) looked at the grocery buying habits of GLP-1 users.
The study found that:
- The initial change in food purchases was positive.
-
- By 6 months of GLP-1 use, grocery spending fell 5.3%, with a notable decrease of snack, sweet, and fast-food purchases.
- But the improved eating habits were short-lived.
-
- After stopping GLP-1 use, 33% of former GLP-1 users reverted to their previous food purchase habits.
-
- Even worse, many of them ended up with less healthy food purchases than before they started.
-
- For example, spending on candy and chocolate increased, suggesting that their cravings came back stronger than before they started on GLP-1 drugs.
Would Supplementation Help?
Whenever you significantly decrease caloric intake, you increase the risk of nutritional deficiencies.
Simply put, every bite counts. When you cut calories, you need to select nutrient dense foods. But that is advice no one is giving GLP-1 users. Again, the results are predictable.
In a recent issue of “Health Tips From the Professor”, I reviewed a recent study on the nutritional adequacy of the diets of GLP-1 users.
That study found that:
- Their diets were high in fat (39% of calories) and saturated fat (13%).
- Their diets were low in fruit, vegetables, grains, and dairy foods.
- Their diets were low in fiber (14 grams). This is half the recommended intake of fiber.
- Their diets were deficient for calcium, iron, magnesium, potassium, choline, vitamin A, vitamin C, vitamin K, vitamin D, and vitamin E.
-
- Long term suboptimal nutrient intakes can have health consequences, but these are deficiencies that can easily be prevented by taking a high-quality multivitamin/multimineral supplement.
- Only 10% were consuming enough protein to prevent the loss of muscle mass associated with GLP-1 use for weight loss, and loss of muscle is a concerning issue.
-
- Most seniors are already struggling to maintain muscle mass.
-
- Loss of muscle mass decreases basal metabolic rate (the rate at which your body burns calories 24 hours a day). This may help explain the rapid weight gain following discontinuation of GLP-1 drugs.
What Does This Mean For You?
GLP-1 drugs may seem like a modern medical miracle. You can effortlessly lose significant weight (15-20% of your starting weight) within a year and a half. But there are two important questions you face.
#1: When you discontinue the GLP-1 drug, what happens next?
- If you stay on the drug, your cumulative risk of serious side effects increases over time – plus you are saddled with burdensome costs for a lifetime.
- If you discontinue the drug without a commitment to permanent lifestyle change (both diet and exercise), your weight will come back – along with the weight-associated risk of serious diseases.
So, my recommendations are obvious. Either:
- Choose programs that include lifestyle change along with GLP-1 drugs, or…
- Enroll in a lifestyle change program and add GLP-1 for additional weight loss once you have become comfortable with your new lifestyle.
And, of course, you should commit to permanent lifestyle change, so you can successfully maintain your new, healthy weight once you have discontinued the GLP-1 drug,
#2: What should you do while on GLP-1 drugs? There are two major concerns to consider:
- Whenever you severely restrict caloric intake, you may have trouble achieving the recommended intake of essential vitamins and minerals.
-
- This is why it is important to select nutrient-dense foods while on GLP-1 drugs – another way of saying the lifestyle change should go hand in hand with GLP-1 drug use.
-
- This is also why a well-designed multivitamin/multimineral supplement is especially important while on GLP-1 drugs.
- Whenever you lose weight quickly, you tend to lose muscle mass – and GLP-1 drugs seem to increase the rate of muscle loss.
-
- Most experts recommend 60-90 grams of protein per day to minimize muscle loss while on GLP-1 drugs. That protein should be spread evenly across meals to maximize absorption and utilization of the protein – which amounts to 20-30 grams of protein per meal. So, my recommendations are:
-
-
- Focus on high-protein foods like lean meats, eggs, Greek yogurt, cottage cheese, tofu, and legumes. Once again, you need to make every bite count.
-
-
-
- Because GLP-1 drugs significantly reduce your appetite, getting all the protein you need high-protein foods will be difficult. This is where protein supplements can play an important role. Choose supplements that are high in protein and low in calories without relying on artificial ingredients.
-
-
-
- And, of course, don’t forget the exercise component. Remember the simple equation: Adequate protein + exercise = muscle
-
The Bottom Line
GLP-1 drugs seem like a modern medical miracle. They allow you to effortlessly lose significant weight and reduce the disease risks associated with obesity.
But does that weight stay off once you discontinue using the GLP-1 drugs? The drug companies would like you to think so. But a recent study suggests that it isn’t true.
The study shows that most people regain the weight, and the associated health risks, within a year and a half of discontinuing GLP-1 drugs. In other words, this study suggests that GLP-1 weight loss is no different than the yo-yo diets of the past.
In this article I review the study and discuss why the weight returns, what role supplements may play, and what this means for you if you are considering a GLP-1 drug for weight loss.
For more information on this study and what it means for you, read the article above.
These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.
___________________________________________________________________________
My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.
My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.
For more detail about FTC regulations for health claims, see this link.
https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance
_____________________________________________________________________
About The Author
Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years. Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”. Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading Biochemistry textbooks for medical students.
Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.
For the past 54 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.