Metabolic Health Beat Weight for Heart Risk in 44 Studies

Jeff's Daily Pick. Across 44 cohort studies, obesity with poor metabolic health went with a 2.10 hazard ratio for cardiovascular disease versus metabolically healthy normal weight (International Journal of Obesity). Normal weight with poor metabolic health often carried more risk than healthy obesity.

Researchers in Iran, the United Kingdom and Norway, led by Asma Kazemi of Shiraz University of Medical Sciences with Dagfinn Aune of Imperial College London, published a meta analysis in the International Journal of Obesity on October 17, 2026. It pooled cohort studies that followed people over time and sorted them by two things at once: body mass index and metabolic health.

What was pooled

The authors searched PubMed and Scopus up to January 2025 and kept 51 publications covering 44 studies. People fell into six groups: normal weight, overweight or obesity, each either metabolically healthy or metabolically unhealthy. The outcomes were cardiovascular disease as a whole, coronary heart disease, heart attack, stroke and heart failure, combined as hazard ratios with random effects models. The abstract does not give one definition of metabolic health, so each source study's own criteria apply.

The numbers

Against people of normal weight with good metabolic health, people with obesity and poor metabolic health had a hazard ratio of 2.10 for cardiovascular disease (95% CI 1.85 to 2.40), 1.97 for coronary heart disease, 2.20 for heart attack, 2.05 for heart failure and 1.55 for stroke. A hazard ratio of 2.10 means roughly twice the rate of events during follow up. It is not a 2.10% risk.

The second finding gives the paper its title. In the authors' words, associations for metabolically unhealthy people of normal weight often exceeded those of metabolically healthy people with obesity. For stroke, poor metabolic health appeared to be the main driver of risk. Weight still mattered: higher BMI and worse metabolic health were each linked to more cardiovascular disease, coronary disease, heart attack and heart failure, and the combination of both was the worst.

The useful point is about screening, not about weight being harmless: a normal BMI says little on its own about blood pressure, blood sugar or blood fats. Our piece on ApoB versus LDL cholesterol looks at one blood marker and how it tracked coronary calcium.