High-protein diets and testosterone

A recent meta-analysis found low-carbohydrate, high-protein diets (> 3.4 g/kg of bodyweight/day) (g/kg/day) decreased men's total testosterone (∼5.23 nmol/L) Whittaker and Harris (2022) Low-carbohydrate diets and men's cortisol and testosterone: systematic review and meta-analysis. Nutrition and Health. DOI: 10.1177/02601060221083079. This finding has generated substantial discussion, however, it has often lacked clarity and context, with the term ‘high-protein’ being used unqualified. Firstly, diets 3.4 g/kg/day), high (1.9–3.4 g/kg/day), moderate (1.25–1.9 g/kg/day) and low ( 3.4 g/kg/day) appear to decrease testosterone, however high- and moderate-protein diets (1.25–3.4 g/kg/day) do not.