Some Commonly Used Medications Can Impede Weight Loss Plans Interview with:

Dr. Zarrinpar

Amir Zarrinpar, MD, PhD
Assistant Professor, Division of Gastroenterology
University of California, San Diego What is the background for this study?

Response: Over the last decade, physicians are beginning to recognize obesity as a disease that requires specific attention; they are more engaged with treating obesity itself rather than its metabolic consequences (such as type 2 diabetes, high blood pressure, cholesterol problems, and/or non-alcoholic fatty liver disease). However, treating obesity is very difficult and many patients don’t succeed in getting the minimum weight loss (approximately 5%) needed to get beneficial health effects. Recent obesity treatment guidelines recommend avoiding placing patients who are obese on obesogenic medication, or medication that have weight gain as a significant side effect.

Despite this recommendation, we noticed many patients who seek treatment for obesity in our clinics are on obesogenic medications. We first noticed that about 40% of patients who are undergoing bariatric surgery at UCSD were prescribed an obesogenic medication. These patients had worse weight loss outcomes compared to patients who did not have any obesogenic medications published that study recently in the International Journal of Obesity.

We wondered whether these findings were specific to bariatric surgery or if patients who were undergoing behavioral treatment (that is, diet and exercise) also had poor weight loss outcomes if they were on obesogenic medications. What are the main findings?

Response: Many of the most commonly prescribed medication in the US have weight gain as a significant side effect. Patients with obesity who are prescribed these medications have poor weight loss results compared to those who are not prescribed these medications.

These findings demonstratively show how important it is to take patients off of these obesogenic medications prior to weight loss treatments. Moreover, it suggests that physician prescription habits could be contributing to the rise of incidence of obesity in the US. We hope that this makes physicians look more critically at the medication list of their patients with obesity and to consider switching obesogenic medications to more weight-neutral or leptogenic (i.e. medication that have weight loss as a significant side effect) options. What should readers take away from your report? 

Response: In many ways, the findings of this study are obvious… patients who take medications that have weight gain as a side effect have trouble losing weight. But three things surprised us about this study.

  • First, the sheer number of patients who were undergoing weight loss treatment who were still on an obesogenic medication (> 60%!) was shocking. If our findings are so obvious, why are so many patients who are trying to fight obesity on these medications that affecting their success?
  • Second, we were surprised by how large of an effect obesogenic medication had on weight loss outcomes. Patients on obesogenic medication were almost 40% less likely to succeed with their weight loss goals. Thus, our understanding of the impact of these medication on weight loss is no longer abstract.
  • Finally, perhaps what has surprised us (as well as our editors) the most has been that this is the first study of its kind. What recommendations do you have for future research as a result of this work? 

Response: We need to start raising clinician awareness of the issue. Ideally a prospective studying involving removing these medications from drug regimens and assessing weight loss will provide more practical data for physicians. Encouraging public awareness of the impact of obesogenic medication on weight loss efforts and encouraging conversation between patients and physicians regarding weight loss efforts is also a positive next step following these findings. Is there anything else you would like to add?

Response: Many of these obesogenic medications have potential alternatives that do not have weight-gain as a side effect. After a thorough evaluation from the clinician, and a discussion with the patient about the possible risks and benefits, altering a patient’s prescription may help in any weight loss efforts.


Desalermos, A. , Russell, B. , Leggett, C. , Parnell, A. , Ober, K. , Hagerich, K. , Gerlan, C. , Ganji, G. , Lee, E. , Proudfoot, J. A., Grunvald, E. , Gupta, S. , Ho, S. B. and Zarrinpar, A. (2019), Effect of Obesogenic Medications on Weight‐Loss Outcomes in a Behavioral Weight‐Management Program. Obesity, 27: 716-723. doi:10.1002/oby.22444

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Apr 25, 2019 @ 2:41 pm

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