A new global study is changing how experts define a “healthy weight.” Researchers found that millions of people with a normal BMI may still have excess belly fat — a condition known as hidden or visceral obesity — and face the same risks for diabetes and heart disease as those who are overweight. The study, published in JAMA Network Open, analyzed data from more than 471,000 adults in 91 countries and found that about 1 in 5 people with a normal BMI had dangerous levels of abdominal fat.
This deep belly fat surrounds vital organs and fuels inflammation, insulin resistance, and other metabolic issues. In the study, people with larger waistlines had an 81% higher risk of diabetes and were far more likely to have high blood pressure and unhealthy cholesterol levels. Experts say this proves that BMI alone can miss major health risks.
Instead, doctors recommend paying attention to waist size — over 32 inches for women and 37 inches for men may signal trouble. The research supports a shift toward measuring body composition and fat distribution rather than focusing on weight alone. Building muscle, staying active, and eating nutrient-rich foods can help reduce hidden fat and protect long-term heart health.
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