The United States has been grappling with an obesity epidemic since the late 1970s, but there is growing evidence that the constantly climbing obesity rates are beginning to drop. "We're seeing signs that there's going to be a turning point," said Benjamin Rader, an epidemiologist at Boston Children's Hospital and at Harvard Medical School who conducts research into health trends using large datasets. In 2024, he and his colleagues published a study based on data from more than 16 million adults, which suggested there had been a decline in obesity prevalence in 2023 — for the first time in more than 10 years.
The National Health and Nutrition Examination Survey also indicated a slight decline between 2021 and 2023. More recent surveys have also provided evidence of declining figures. This comes as a series of new drugs, which some people are using for weight loss, have come onto the market.
The use of the GLP-1 agonist drugs Ozempic, Wegovy and Zepbound has increased rapidly in recent years in the US, with prescriptions more than quadrupling between 2021 and early 2026. Some of the active ingredients in these drugs were originally developed to treat Type 2 diabetes by mimicking a naturally occurring intestinal hormone to promote a feeling of fullness and to slow down gastric emptying. This has led to many patients losing a significant amount of weight.
To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video For Rader, "it seemed like it [the impact of this medicine] was bound to show up in the data" and that it was possible to be "moderately confident that drugs themselves were having an effect." For Peminda Cabandugama, an endocrinologist and spokesperson for The Obesity Society, which provides support to professionals in the obesity field, "there is strong evidence showing that there is a significant decline in obesity." In a written statement to DW, he said the "general opinion is that GLP-1 medications and their combinations and their increased use as well as the recent attention put on the importance of weight management have played a large and direct role in this reduction in obesity prevalence." But for Rader there is no definitive proof of a causal relationship. He has no doubt that the drugs have led to weight loss in many people at an individual level, but he told DW that it was too soon to say whether it "will lead to a plateau, […] a decrease […] or a slower decrease in the next 20 years" and what the effect on the general population might be. Cabandugama thinks the current figures might also have been influenced by lifestyle changes during and after the COVID-19 pandemic, and points out that "these trends are likely a confluence of multiple elements that include the increased use of anti-obesity medications, post-pandemic behavioral changes, increased awareness about the importance of weight management etc." Some researchers in the US don't believe obesity rates will decline permanently.
A study by the Institute of Health Metrics and Evaluation (IHME) at the University of Washington in Seattle predicts a rise in rates through 2035 and suggests that the proportion of obese adults could increase from 42.5% in 2022 to 46.9% in 2035. Though Rader doesn't necessarily consider such predictions to be wrong, he pointed out that many prediction models are based on data from before the boom in GLP-1 drugs and might not take into account their potential effects. In an article for the Journal of the American Medical Association, he warned that the models could overestimate the future burden of obesity.
The authors of the IHME study have not entirely dismissed this criticism, but they did point out that to date only a small proportion of obese people use such drugs and that many patients discontinue treatment within a year. They added that some people gain weight again after initially losing it, and more representative data was needed to assess whether such drugs will have a lasting effect on obesity rates. Cabandugama has also urged caution, saying that while there are currently strong signs of a decline, "the general consensus is that it is still too early to tell whether this is a true trend reversal." Though for a long time, obesity was viewed primarily as a result of an individual's lifestyle, it has since become well-known that this complex chronic condition is caused by a combination of biological, genetic, social and psychological factors.
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