For years, the medical community has approached obesity in older adults with a degree of caution. While excess weight in one’s 30s or 40s is often viewed through the lens of prevention, obesity in those over 65 is complicated by the realities of aging: muscle loss, frailty, and a cocktail of co-existing health conditions. The fear has long been that aggressive weight loss in seniors might do more harm than good, potentially accelerating the loss of lean muscle mass or triggering adverse reactions in medically vulnerable patients.
However, a new analysis of the landmark STEP clinical trials suggests that semaglutide—the active ingredient in the widely discussed medications Wegovy and Ozempic—is not only effective but generally safe for adults over the age of 65. The findings, led by Prof. Luca Busetto of the University of Padova in Italy, indicate that older adults can achieve substantial weight loss and significant improvements in cardiometabolic health, mirroring the results seen in younger populations.
As a physician, I have seen firsthand how obesity in later life can act as a multiplier for disability, making simple tasks like walking or dressing more difficult. This study provides critical evidence that the benefits of GLP-1 receptor agonists may outweigh the risks for a demographic that has historically been underrepresented in obesity drug trials.
Measuring Success: Beyond the Scale
To arrive at these conclusions, researchers analyzed data from a suite of trials—STEP 1, 3, 4, 5, 8, and 9. The analysis focused specifically on participants aged 65 and older who had obesity or were overweight with at least one obesity-related complication, but who did not have diabetes. This distinction was vital; because weight loss results are typically lower in patients with diabetes, excluding them allowed researchers to isolate the drug’s efficacy in treating obesity specifically.
The results were striking. Over a 68-week period, participants receiving a weekly 2.4 mg dose of semaglutide, combined with lifestyle interventions, lost an average of 15.4% of their body weight. In contrast, the placebo group lost only 5.1%. The impact extended beyond total weight to the distribution of fat, with semaglutide users seeing a reduction in waist circumference of 14.3 cm, compared to 6.0 cm in the placebo group.
The study also tracked “milestones”—specific percentages of weight loss that often correlate with significant health improvements. The disparity between the medication and the placebo was stark:
| Weight Loss Milestone | Semaglutide Group (%) | Placebo Group (%) |
|---|---|---|
| At least 10% weight loss | 66.5% | 15.5% |
| At least 15% weight loss | 46.8% | 6.4% |
| At least 20% weight loss | 28.6% | 2.7% |
Perhaps more important than the raw number on the scale was the shift in BMI categories. Twenty-seven percent of the semaglutide group reached a BMI of less than 27 kg/m², which the researchers categorized as a healthy weight—a feat achieved by only 5.5% of the placebo group.
Improving the “Internal” Health Profile
While weight loss is the most visible outcome, the “invisible” wins are where the real clinical value lies for older adults. Obesity in seniors is a primary driver of hypertension, dyslipidemia, and insulin resistance, all of which increase the risk of stroke and heart attack.
The analysis found that semaglutide users experienced marked improvements in several key cardiometabolic risk factors. These included reductions in blood pressure and improvements in cholesterol and blood fat levels. Researchers also noted a decrease in glycated hemoglobin (HbA1c), a critical marker of blood sugar control, suggesting that the drug helps stabilize metabolic health even in those who do not yet have a diagnosis of diabetes.
The study also looked at the waist-to-height ratio (WHtR), a metric many clinicians prefer over BMI because it specifically targets abdominal obesity, which is more closely linked to cardiovascular disease. In the semaglutide group, 11.3% achieved a WHtR of less than 0.53, compared to just 4.5% in the placebo group.
Balancing Efficacy with Safety and Frailty
The central question for any treatment in the 65+ demographic is safety. Older adults are often more susceptible to side effects due to decreased kidney function or the use of other medications. The study found that overall adverse events (AEs) were similar between the two groups, with 89.1% of semaglutide users reporting some form of AE compared to 84.5% of the placebo group.
However, there was a notable increase in serious adverse events in the semaglutide group (19.0% vs. 12.7% in the placebo group). Common side effects included constipation and dizziness, both of which can be particularly problematic for older adults, potentially increasing the risk of falls.
Crucially, the researchers monitored for two specific fears associated with GLP-1 drugs in the elderly: bone fractures and hypoglycemia (dangerously low blood sugar). The rates for both were low—affecting less than 1% of participants in both the semaglutide and placebo groups—suggesting that the drug does not significantly increase the risk of these severe complications when used as directed.
Prof. Busetto emphasized that the safety and efficacy profile of semaglutide in this age group was consistent with the broader STEP program. “In many high-income countries, the majority of cases of excess weight actually occur in adults aged 65 years and over,” Busetto noted, adding that this population represents a major driver for obesity-related complications and reduced quality of life.
Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or treatment.
As the medical community continues to integrate GLP-1 therapies into standard care, the next step will be long-term observational data to determine how this weight loss affects muscle preservation (sarcopenia) in the elderly over several years. Clinicians are expected to keep a close watch on the balance between fat loss and muscle maintenance as more seniors begin these regimens.
Do you have questions about how weight loss medications affect older adults? Share your thoughts or experiences in the comments below.
