Though popular weight loss pills for obesity continue to generate substantial weight loss, most do not generate meaningful improvements in overall quality of life after a year of treatment, according to a large international study.
The study, published in The BMJ, included 262 clinical trials with almost 100,000 people, assessing 19 weight loss drugs. The results indicate that while the compounds do effectively help to lose weight, their potential for overall health benefits may not be as great as once thought.
More weight loss was invariably associated with more side effects and higher rates of treatment discontinuation, researchers said.
The study found that health-related QL did not significantly improve after most of the medications with lifestyle changes alone. In both clinical trials, the participants filled out questionnaires that assessed physical and mental health and well-being, and the researchers noted only slight variations between the groups taking medication and the groups using diet and exercise programs.
Tirzepatide (the drug in Mounjaro and Zepbound) had the most significant weight loss, among the treatments studied. CagriSema, which is not yet approved for clinical use, was also one of the best treatments for body weight reduction.
Among the most well-established treatments for obesity management and patients with associated health issues, semaglutide (the drug found in Ozempic and Wegovy) has demonstrated the most robust effects when it comes to reducing the risk of death and major cardiovascular events.
Even with these advantages, the researchers discovered that lean body mass—muscle, bone, and other tissues without fat—was decreased by both tirzepatide and semaglutide. Reduced lean mass has been associated with an increased risk of falling, fractures and other health issues, especially in the elderly.
The authors noted that many of the clinical trials involved a relatively short period of follow-up, which makes it difficult to fully evaluate the safety and effectiveness of newer drugs. They urged more long-term studies to better understand the long-term effects of these drugs on patients.
Additional caution was recommended by independent experts to interpret the findings relative to quality of life. Marie Spreckley of the University of Cambridge pointed out that there are many individual and social determinants that questionnaires may not adequately reflect, and that these factors impact quality of life.
The researchers also pointed out that obesity has been identified as a chronic medical condition and is now known to need a more comprehensive treatment method. They stated that a narrow measure of success, such as body weight, could miss other key indicators of success, such as physical function, mental health and overall well-being.
The results support the notion that losing weight alone is not enough to benefit all health aspects, said José M. Ordovás, Ph.D., of Tufts University, who was not a part of the study.
Treatment for obesity should be based on a broader set of outcomes, such as health, daily function and quality of life, he said, not just on what is reflected on the scales.
