New Obesity Definition Sparks Shift In Health And Food
The way we define and tackle obesity in the United States is undergoing a seismic shift, one that could upend decades of medical practice, reshape grocery shopping, and change how millions of Americans approach their health. On October 15, 2025, a landmark study published in JAMA Network Open challenged the long-held reliance on body mass index (BMI) as the sole indicator of obesity, proposing a more nuanced framework that incorporates body fat distribution and organ health. Just days later, on October 27, Thrive Market—a major online grocer—responded to the surging demand for weight-loss support by launching a new filter specifically for customers using GLP-1 medications, a class of drugs revolutionizing weight management and consumer behavior.
For decades, BMI—a simple ratio of weight to height—has been the go-to metric for diagnosing obesity. Yet, as JAMA Network Open and The Lancet Diabetes & Endocrinology have now emphasized, BMI alone doesn’t capture the full picture. It ignores where fat is distributed, how much is muscle versus fat, and whether excess weight is already affecting organs. Dr. Lindsay T. Fourman, lead author of the JAMA Network Open study, and her colleagues introduced a new classification system: “BMI-plus anthropometric obesity” (BMI above the traditional threshold and at least one elevated body measurement, or BMI over 40), and “anthropometric only obesity” (at least two elevated body measurements but a BMI below the traditional cut-off). Furthermore, obesity is now divided into “clinical” and “pre-clinical” categories, depending on whether organ dysfunction or physical limitations are already present.
The implications are staggering. According to the study, nearly 80% of people aged 70 and older qualified as obese under the new guidelines—far more than would have been captured by BMI alone. Nationwide, about 70% of U.S. adults now fall under the obesity category using this modern framework, a dramatic jump from the previous 43%. This redefinition means millions who were previously overlooked—those with only slightly elevated BMI but high-risk body measurements or early organ impairment—are now recognized as being at significant risk for diabetes, heart disease, and other complications.
Why does this matter so much? Because this new approach doesn’t just change the numbers—it changes the entire strategy for prevention and treatment. As JAMA Network Open reported, the updated classification enables clinicians to identify at-risk individuals earlier and tailor interventions more precisely. For example, anti-obesity medications, which were traditionally prescribed based on BMI thresholds, could now be offered to those with clinical obesity—even if their BMI is below the old cut-off—while those without organ dysfunction might focus on lifestyle changes instead.
Personalized interventions are now the name of the game. For those with pre-clinical obesity, targeted diet, exercise, and behavioral programs can help prevent progression to more severe health problems. But this also means that screening programs, treatment guidelines, and healthcare resources must adapt to accommodate the vastly increased number of people now identified as obese. “By classifying obesity as BMI-plus anthropometric or anthropometric only and distinguishing clinical versus pre-clinical, this framework allows for a more accurate identification of individuals at risk,” the study concluded.
These changes are rippling far beyond the doctor’s office. As Americans become more attuned to nuanced definitions of obesity and new weight-loss medications, the food industry is scrambling to keep up. Thrive Market’s recent launch of its “GLP-1 Friendly” filter is a prime example. According to Grocery Dive, Thrive Market observed a steady increase in searches related to GLP-1 medications over the past year. April Lane, Thrive’s Chief Merchandising Officer, explained that the company created the new filter after noticing shifts in shopper behavior and basket activity, especially during periods like post-winter holidays and back-to-school season.
The GLP-1 Friendly filter prioritizes foods with lean protein and fiber while excluding items containing sugar alcohols, high-intensity sweeteners, refined carbohydrates, excess saturated fat, and even spicy foods—which can irritate the stomach or slow digestion for those on GLP-1 drugs. More than 1,000 products, spanning both national and private label brands, are now included under this filter, which joins Thrive’s suite of over 100 specialized filters like “Gluten-Free” and “Keto.”
Why such a dramatic shift in grocery offerings? Because GLP-1 medications are changing what—and how much—people eat. A Harvard Business Review analysis by PwC found that grocery spending dropped 6% to 8% within a year in households where a GLP-1 user was the primary food purchaser. “The shift in consumer spending away from calorie-dense, convenience-driven items toward functional, nutrient-rich options poses a direct challenge to food retailers with long-standing demand models based on volume and loyalty,” the study noted. As more Americans use these drugs, grocers are being forced to rethink their entire approach to product selection and marketing.
But weight management isn’t just about what you eat or what medications you take—it’s also about how you move. On October 28, research highlighted by The Conversation made it clear that while exercise alone often leads to only modest weight loss (thanks to factors like increased appetite and reduced activity outside workouts), it’s crucial for keeping the weight off once it’s lost. In a study of over 1,100 people, physical activity had little impact on initial weight loss, but those who stayed active after losing weight were much more likely to maintain their progress. Exercise also brings a host of other benefits: improved cholesterol, lower inflammation, better blood sugar control, and greater insulin sensitivity—all of which reduce the risk of heart disease and type 2 diabetes.
Interestingly, the combination of exercise and weight-loss drugs like Saxenda appears to help people maintain weight loss better than drugs alone. Exercise raises total daily energy expenditure, which helps offset the drop in resting metabolism that occurs with weight loss. Resistance training, in particular, preserves or rebuilds muscle mass, keeping metabolism higher and aiding long-term weight maintenance. Aerobic exercise burns calories and enhances the body’s ability to burn fat for fuel, while resistance training supports muscle health—both are essential for lasting results.
Physical activity isn’t just about the numbers on the scale, either. It improves sleep, mood, and stress levels, reduces the stress hormone cortisol (which can lead to fat storage), and helps regulate appetite and blood glucose. As the research emphasized, everyone responds differently to exercise, but its benefits for physical and mental health are universal.
So, what should Americans do with all this new information? Experts advise moving beyond BMI: ask your doctor about measuring waist circumference, waist-to-hip ratio, or even body fat scans. Adopt healthier habits with regular exercise, a balanced diet, and strength training. And keep an eye on metabolic markers like cholesterol and blood sugar, which can offer early warning signs of trouble.
As the definition of obesity evolves and consumer habits shift, both the healthcare system and the food industry are being forced to adapt. The message is clear: understanding obesity requires more than a bathroom scale—it demands a holistic look at body composition, organ health, and lifestyle. Only then can we truly address the growing epidemic and help Americans live healthier, longer lives.
link
