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University of Virginia Researchers Challenge Traditional Focus on Weight Loss
As the obesity epidemic continues to rise in the United States, so too does the pressure to lose weight, often through the use of weight-loss drugs. But a new study from the University of Virginia (UVA) suggests that the focus on weight loss may be misguided. Instead, researchers say that improving fitness—regardless of body weight—could be the key to living longer, healthier lives.
The study, published in the British Journal of Sports Medicine, found that cardiorespiratory fitness (a measure of how well the heart and lungs function during exercise) is a far stronger predictor of health outcomes than body weight. According to the researchers, people who are fit, even if classified as “obese” based on their body mass index (BMI), are at a similar risk for death and cardiovascular disease as their normal-weight, fit counterparts. In contrast, normal-weight individuals who are unfit face a significantly higher risk of mortality.
“Fitness, it turns out, is far more important than fatness when it comes to mortality risk,” said Siddhartha Angadi, associate professor of exercise physiology at UVA and corresponding author of the study. “Our study found that obese fit individuals had a risk of death that was similar to that of normal-weight, fit individuals, and close to one-half that of normal-weight, unfit individuals.”
The study analyzed data from 20 large epidemiological studies, including over 398,000 adults from multiple countries. The findings underscore a key message: optimal health outcomes may be more effectively achieved through improving cardiorespiratory fitness rather than solely focusing on weight loss.
The researchers noted that traditional approaches to health often prioritize weight loss, despite its challenges and associated risks. For many individuals, losing weight can be difficult, and repeated cycles of weight loss and regain—commonly referred to as “yo-yo dieting”—can actually be harmful to health, increasing risks of cardiovascular disease, diabetes, and other conditions.
“Most people who lose weight regain it,” said Glenn Gaesser, professor at Arizona State University and co-author of the study. “Repetitive cycles of losing and gaining weight are associated with numerous health risks comparable to those of obesity itself. Improving aerobic fitness may help avoid the adverse health effects associated with chronic yo-yo dieting.”
The study also highlights the importance of physical activity. Currently, only about 20% of adults in the U.S. meet the recommended physical activity guidelines from the Department of Health and Human Services. These guidelines suggest that adults should engage in 150 minutes of moderate-intensity exercise or 75 minutes of vigorous exercise each week, along with muscle-strengthening activities twice a week.
Even modest increases in physical activity can make a significant difference. According to Angadi, “The largest reduction in all-cause and cardiovascular disease mortality risk occurs when completely sedentary individuals increase their physical activity or exercise modestly.” Simple activities like brisk walking, a few times a week, can have a profound impact on overall health.
The research contributes to the ongoing “fitness vs. fatness” debate, offering strong evidence that fitness levels are a much more reliable indicator of health than body weight. Nathan Weeldryer, a doctoral student at UVA and co-author of the study, believes the findings could help shift public perception about health and weight. “We tend to equate body weight or fatness with health status, but our study suggests that fitness is a far more important factor.”
As the global fight against obesity continues, the study encourages a broader focus on improving fitness as a pathway to better health for people of all body sizes. “Exercise is more than just a way to expend calories. It is excellent ‘medicine’ to optimize overall health and can largely reduce the risk of cardiovascular disease and all-cause death for people of all sizes,” Angadi said.
For individuals struggling with weight or fitness, the research offers a hopeful message: focus on becoming fit rather than obsessed with losing weight. The path to better health may not be through the scale, but through increased physical activity and improved fitness.
For more information, the study can be accessed in the British Journal of Sports Medicine.
Study Reference:
Nathan R. Weeldreyer et al, “Cardiorespiratory fitness, body mass index and mortality: a systematic review and meta-analysis,” British Journal of Sports Medicine (2024). DOI: 10.1136/bjsports-2024-108748
