Study Links Higher Body Fat to Reduced Male Fertility

A recent Danish cross‑sectional study of 1,058 young men (average age 19) found that higher body‑fat percentages are associated with lower sperm counts and altered reproductive hormone levels. Men with 20‑24 % body fat produced about 23 % fewer sperm than those with 8‑19 % body fat, and those with ≥25 % body fat showed reduced testosterone and SHBG, but increased LH and estradiol. Researchers suggest body‑fat percentage predicts sperm quality better than the traditional Body‑Mass‑Index (BMI).

In parallel, health information on BMI calculators emphasizes that while the BMI provides a quick estimate of weight classification, it does not differentiate between fat and muscle and omits other health factors. Guidelines from the World Health Organization and the German Obesity Society outline BMI ranges for underweight, normal weight, overweight and obesity, and note that BMI is not a diagnostic tool, especially for children and adolescents.