..Mean ± SD serum testosterone was 435.5 ± 6.7 ng/dl. Mean testosterone was lower among men with a low fat diet (410.8 ± 8.1 vs 443.5 ± 7.3, p=0.005) and a Mediterranean diet (412.9 ± 9.1 vs 443.5 ± 7.3, p=0.002). Multivariable analysis controlling for age, body mass index, activity level, diabetes, comorbidities and prostate cancer showed that men with a nonrestrictive diet had higher serum testosterone than those adhering to a low fat diet (ß –57.2, 95% CI –105.6 to –8.8, p <0.05).
Men adhering to low fat diets had lower serum testosterone levels even when controlling for comorbidities, age, body mass index and activity levels. As differences in serum testosterone between the diets were modest, the avoidance of fat restrictive diets should be weighed against the potential benefits on an individual basis.