Data strongly suggest that lower BMI is better for heart disease. A new study analyzing genetic mutations predisposing to increased body mass index (BMI) provides strong evidence that higher BMI plays a causal role in type 2 diabetes, hypertension, and coronary heart disease (CHD). For the study, researchers analyzed genetic, medical, and sociodemographic information from 120,000 individuals included in the UK Biobank. A polygenic risk score comprising 93 single-nucleotide polymorphisms associated with BMI from previous genome-wide association studies was constructed.

Using the genetic data, results showed that each 4.8 unit increase in BMI was associated with a 35% increased risk of CHD (odds ratio [OR] 1.35; 95% CI 1.09–1.69); a 64% increased risk of hypertension (OR 1.64; 95% CI 1.48–1.83); and a 153% increased risk of type 2 diabetes (OR 2.53; 95% CI 2.0–43.13).