Research
Macro partitioning
High-fat diets (specifically ketogenic diets with >75% fat) increase total and free testosterone in resistance-trained men compared to Western diets, likely due to higher cholesterol intake supporting steroidogenesis.
If you are resistance training, ensure you consume enough dietary fat (at least 25% of calories). Very low-fat diets may suppress testosterone. Some evidence suggests ketogenic diets (high fat, very low carb) may further boost testosterone in trained men, likely due to cholesterol availability for hormone synthesis.
ModerateSupportsMEDIUM confidence
Results indicated that both groups experienced a significant increase from baseline in both total testosterone (TT) and FT concentrations... It has been suggested that increases in testosterone concentrations resulting from a KD are related to the high dietary intake of cholesterol [88].
Why this rating
Studies are small (n=13-25) and often lack long-term controls or low-fat comparators in the same study design.
Source
Manipulation of Dietary Intake on Changes in Circulating Testosterone Concentrations
Amit Zamir et al. · Nutrients · 2021
DOI 10.3390/nu13103375
narrative_reviewCited 23×
Read the paper DOI resolved against Crossref · corpus check 2026-06-10
More from this paper
- Maintaining energy availability above 30 kcal/kg fat-free mass per day is required to prevent significant reductions in circulating testosterone; deficits below this threshold suppress luteinizing hormone (LH) and subsequently lower testosterone.Good
- Soy protein supplementation may blunt the acute post-exercise testosterone response compared to whey protein or placebo, although it does not necessarily lower resting total testosterone.Moderate
Related findings · Macro partitioning
- Total daily protein intake of 1.6 g/kg/day is sufficient for maximizing resistance training-induced muscle gains, with an upper confidence interval of 2.2 g/kg/day.Strong
- Resistance exercise training combined with sufficient dietary protein intake acts synergistically to maximize skeletal muscle hypertrophy, with protein intake saturating around 1.6 g/kg/day for general populations and potentially requiring 2.0-2.2 g/kg/day for resistance-trained individuals.Strong
- Trans fats should be completely eliminated from the diet, as they increase LDL cholesterol, decrease HDL cholesterol, and are directly associated with increased coronary risk.Strong
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