Certain weight loss medications may be recommended for individuals when they are not having success with their weight loss goals through lifestyle change alone. The efforts to make behavior changes to lose weight look very different from person to person. Success generally increases with the help and guidance of a specialized care team, which may include a nutritionist or dietitian. Even when a medication is prescribed, it is still recommended to maintain a dedication to lifestyle change and have additional guidance and support for changing behaviors (more on that later).

Research varies greatly on the effectiveness of these weight loss drugs due to differences in medication dosing, study population differences, and study design. Short-term data does reveal a promising influence on weight change (between 5–23% total body weight loss over various time frames). However, long-term weight loss data is limited for many of these medications as the majority of them were approved only in the last decade. This means that we simply do not know how well the addition of these medications will support long-term behavior change beyond the data that is being collected in real-time.

Real-World Success Rates of Weight Loss Drugs

 
Additionally, we know that even the best study design with positive outcomes can be hard to recreate in a real-world setting. One review summarized results from 41 different studies done within a real-world setting. They found that successful weight loss, defined as greater than or equal to 5% total body weight loss in 3–6 months, was observed in 14–58.6% of patients. The use of these medications was associated with mild to moderate side effects that influenced long-term use. It was estimated that less than 43% of participants were still taking liraglutide (Saxenda) by 6 months, meaning more than half of participants ended up stopping their medication at that time (1). Another review, including data from 10 separate studies for tirzepatide (Zepbound), showed that the incidence of gastrointestinal side effects increased with each increase in medication dose. This occurred in 39–49% of patients, with 10% of them discontinuing their medications due to the side effects they were experiencing (4).

Behavior Change is Still the Key to Weight Loss

 
These medications for weight loss are not going away anytime soon. The reality is that with or without these medications, there is no magic bullet for successful behavior change leading to weight loss. You are looking at a good 6–12 months of working hard to make sustainable and healthy lifestyle changes. When done with a trained behavior change expert, like a dietitian, for at least 14 visits over 6 months, your success rate is higher (3). If you choose to take medication for the purpose of losing weight, it is important to let your doctor and anyone else on your care team know.

Should You Use Weight Loss Medication?

 
In summary, it is a very personal decision between you and your doctor to include a weight loss medication to assist in weight loss. With any medication, it is important to ask questions to help you decide what is best for you. Some have been included below for reference. Behavior change is not easy and takes time and diligence. Working with an expert who can help support you in your journey is crucial for long-term weight loss success. There is no magic bullet, but working with a guided care team can increase your chances of success.

Questions to Ask Before Starting Medication for Weight Loss

• How do these medications work?
• What happens if I stop taking this?
• How long do I need to take this medication?
• What side effects can I expect?

References

1. Slavin JL. Dietary fiber and body weight. Nutrition. 2005;21(3):411-418. doi:10.1016/j.nut.2004.08.018

2. Mytton OT, Nnoaham K, Eyles H, Scarborough P, Mhurchu CN. Systematic review and meta-analysis of the effect of increased vegetable and fruit consumption on body weight and energy intake. BMC Public Health. 2014;14:886. doi:10.1186/1471-2458-14-886

3. Johnston CS, Day CS, Swan PD. Postprandial thermogenesis is increased 100% on a high-protein, low-fat diet versus a high-carbohydrate, low-fat diet in healthy, young women. J Am Coll Nutr. 2002;21(1):55-61. doi:10.1080/07315724.2002.10719191

4. Ledoux TA, Hingle MD, Baranowski T. Relationship of fruit and vegetable intake with adiposity: a systematic review. Obes Rev. 2011;12(5):e143-e150. doi:10.1111/j.1467-789X.2010.00786.x

5. Leidy HJ, Clifton PM, Astrup A, et al. The role of protein in weight loss and maintenance. Am J Clin Nutr. 2015;101(6):1320S-1329S. doi:10.3945/ajcn.114.084038

6. McKeown NM, Yoshida M, Shea MK, et al. Whole-grain intake and cereal fiber are associated with lower abdominal adiposity in older adults. J Nutr. 2009;139(10):1950-1955. doi:10.3945/jn.109.108555

7. Estruch R, Ros E, Salas-Salvadó J, et al. Primary prevention of cardiovascular disease with a Mediterranean diet. N Engl J Med. 2013;368(14):1279-1290. doi:10.1056/NEJMoa1200303

8. Hall KD, Ayuketah A, Brychta R, et al. Ultra-processed diets cause excess calorie intake and weight gain: an inpatient randomized controlled trial of ad libitum food intake. Cell Metab. 2019;30(1):67-77. doi:10.1016/j.cmet.2019.05.008

9. Schwingshackl L, Hoffmann G, Lampousi AM, et al. Food groups and risk of type 2 diabetes mellitus: a systematic review and meta-analysis of prospective studies. Eur J Epidemiol. 2017;32(5):363-375. doi:10.1007/s10654-017-0246-y