Study finds body fat percentage better predictor of men's reproductive health than BMI

A recent large‑scale study of over 1,000 Danish men has suggested that body fat percentage may serve as a more reliable marker of reproductive health than the widely used body mass index (BMI). Researchers measured participants’ fat mass using dual‑energy X‑ray absorptiometry and compared the results with indicators of male fertility, including sperm concentration, motility, morphology and circulating testosterone levels. The analysis revealed stronger, statistically significant associations between higher body fat percentages and poorer sperm quality and lower testosterone than those observed with BMI.

The findings highlight a limitation of BMI, which does not distinguish between fat and lean mass or account for fat distribution. By contrast, direct assessment of adiposity appears to capture the metabolic and endocrine changes that influence reproductive function. The study’s authors recommend that clinicians consider incorporating body composition measurements into routine evaluations of male fertility, particularly for men presenting with suboptimal reproductive outcomes.