Macros and Testosterone: What the Research Suggests

Most conversations about nutrition and testosterone focus on specific foods or supplements. While individual foods matter, the macronutrient composition of your overall diet may matter more for hormonal health than any single ingredient. How much fat, carbohydrate, and protein you eat, and in what proportions, is associated with the hormonal environment in which testosterone is produced, converted, and utilized.

This is not about following a rigid meal plan. It is about understanding the biochemical relationships between the food you eat and the hormones your body produces, then applying that understanding to build an eating pattern that supports healthy hormone function without requiring obsessive tracking or eliminating entire food groups.

Why Macronutrient Balance Matters for Hormones

Testosterone is a steroid hormone, and all steroid hormones share the same precursor molecule: cholesterol. The synthesis pathway begins with cholesterol being transported into the mitochondria of Leydig cells in the testes, where it is converted through a series of enzymatic reactions into pregnenolone, then progesterone, and finally testosterone. Conversion of cholesterol to pregnenolone is the first and rate-limiting step of steroid hormone production.^[8]

But the story extends beyond fat and cholesterol. Carbohydrates influence insulin and cortisol levels, both of which modulate testosterone production. Protein provides the amino acids needed for enzyme synthesis and tissue repair, but very high protein intake can displace the fat and carbohydrate calories discussed below. Caloric intake itself matters: severe, prolonged energy deficits are associated with suppression of the hypothalamic-pituitary-gonadal (HPG) axis.

The evidence suggests that balance matters more than extremes. Diets that drastically cut fat, or that push protein very high at the expense of carbohydrate, have been associated with lower testosterone in small studies, while moderate approaches that provide adequate energy and all three macronutrients are the safer default. Most of this research is short-term and in small groups, so treat it as direction rather than precision. For a closer look at one restrictive pattern, see our article on the ketogenic diet and testosterone.

Dietary Fat: The Testosterone Foundation

Of the three macronutrients, dietary fat has the best-documented relationship with testosterone levels. Controlled diet studies comparing lower-fat and higher-fat eating patterns have generally found lower total and free testosterone on the lower-fat diet.^[2]

A 1984 study in the Journal of Steroid Biochemistry followed 30 healthy men who replaced their usual diet (40 percent of energy from fat) with one providing 25 percent of energy from fat for six weeks. Mean total testosterone fell from 22.7 to 19.3 nmol/L (about 15 percent), free testosterone fell as well, and the changes reversed afterward.^[1] A 2021 meta-analysis in the Journal of Steroid Biochemistry and Molecular Biology, covering six intervention studies and 206 men, found significantly lower total, free, and urinary testosterone on low-fat diets compared with high-fat diets, although the authors note that more randomized trials are needed.^[2]

The type of fat also matters, though perhaps not in the way popular culture suggests. Both saturated fat and monounsaturated fat appear to support testosterone production, while the evidence on polyunsaturated fat is more mixed. In a small observational study of 12 resistance-trained men in the Journal of Applied Physiology, resting testosterone correlated positively with percent of energy from fat (r = 0.72), saturated fat (r = 0.77), and monounsaturated fat (r = 0.79), and negatively with percent of energy from protein (r = -0.71). Correlation does not prove cause, and the group was small.^[9]

Practical fat sources that support testosterone production include extra virgin olive oil (rich in monounsaturated fat and polyphenols), eggs (whole eggs including the yolk, which contains cholesterol and fat-soluble vitamins), avocados, nuts (especially almonds and macadamia nuts), fatty fish (salmon, sardines, mackerel), and moderate amounts of butter and coconut oil. For a comprehensive guide to specific foods, see our foods that boost testosterone article.

Carbohydrates: The Cortisol Connection

Carbohydrates have a complex relationship with testosterone that works primarily through two mechanisms: their relationship with cortisol and with sex hormone-binding globulin (SHBG). The research here is smaller and more mixed than for fat.

Cortisol and testosterone: In a 1987 Life Sciences study, seven healthy men ate a high-carbohydrate diet and a high-protein diet, matched for calories and fat, for ten days each. On the high-carbohydrate diet, testosterone was higher (468 versus 371 ng/dL) and cortisol was lower (7.7 versus 10.6 µg/dL).^[3] Cortisol and testosterone tend to move in opposite directions under stress, which is why this ratio is watched in training research, but a seven-man study is only suggestive.

This is particularly relevant for men who train intensely. In a study in the European Journal of Applied Physiology, male participants did three consecutive days of intensive endurance training while eating either about 60 percent or about 30 percent of their intake as carbohydrate. The free testosterone-to-cortisol ratio fell by 43 percent in the low-carbohydrate group and was essentially unchanged (-3 percent) in the higher-carbohydrate group.^[10] That ratio is used as a marker of training stress, not a diagnosis of anything.

SHBG: SHBG is the protein that binds testosterone in the blood. In the same 1987 study, SHBG moved in parallel with testosterone, and was higher on the high-carbohydrate diet (32.5 versus 23.4 nmol/L).^[3] In other words, diet can shift both total testosterone and the proteins that carry it, which is one reason a single blood number is hard to interpret without a clinician.

Low-carbohydrate and ketogenic communities often cite studies showing testosterone gains on their protocols, and the evidence is genuinely mixed. A 2022 systematic review and meta-analysis in Nutrition and Health (27 studies, 309 men) found that cortisol rises during the first weeks of a low-carbohydrate diet, and that high-protein, low-carbohydrate diets were associated with a large decrease in resting total testosterone (about 5 nmol/L).^[4] Small trials differ by protein intake, duration, and the men studied, so no single pattern is proven best.

A practical, balanced starting point for many men is roughly 40 to 50 percent of calories from carbohydrates, adjusted for activity level. This range is a coaching convention rather than a study-defined optimum: highly active men may prefer the higher end, and more sedentary men the lower end. Whole grains, root vegetables, fruits, legumes, and rice are sensible primary sources.

Protein: Finding the Sweet Spot

Protein is essential for muscle repair, enzyme synthesis, and countless metabolic functions. But when it comes to testosterone specifically, the relationship follows an inverted-U curve: too little impairs hormonal function, but very high intakes have been associated with lower testosterone in small studies. This pattern is plausible but not firmly established.

Two lines of evidence point in this direction. First, in the 1987 seven-man crossover study described above, testosterone was lower on the high-protein diet than on the high-carbohydrate diet.^[3] Second, the 2022 meta-analysis found that high-protein, low-carbohydrate diets were associated with a large decrease in resting total testosterone.^[4] Why this happens is not settled; displacing carbohydrate or fat calories is one hypothesis.

On the other end, inadequate protein intake limits muscle repair and recovery, which is why most training-focused guidance still sets a protein floor.

A reasonable range for most training men is 0.7 to 1.0 grams of protein per pound of body weight per day, which is roughly 20 to 30 percent of calories for many people. A meta-analysis of 49 trials found that protein intakes above about 1.6 g/kg per day (roughly 0.7 g/lb) did not produce further gains in fat-free mass,^[7] so there is little reason to push far above this range, and it leaves room for the fat and carbohydrate intakes discussed above. For a deeper exploration, read our guide on protein and testosterone.

Cholesterol as a Testosterone Precursor

Dietary cholesterol has been unfairly demonized for decades. Cholesterol is a direct and essential precursor to all steroid hormones, including testosterone, cortisol, and estrogen.^[8] The body makes most of the cholesterol it needs itself, so dietary cholesterol is not a required input, but whole foods that contain it (eggs, shellfish, meat) are also rich in other nutrients.

A 2017 trial in the American Journal of Clinical Nutrition found that, after resistance exercise, ten young men had a greater muscle protein synthetic response to whole eggs than to egg whites with the same protein. That study measured muscle protein synthesis, not testosterone, so it does not show that dietary cholesterol raises testosterone; it simply suggests whole foods can do more than their protein content alone.^[11]

Practical application: include cholesterol-containing foods in your diet, particularly eggs, shellfish, and moderate amounts of red meat. If you have high cholesterol, familial hypercholesterolemia, or heart disease risk factors, follow your doctor's advice on dietary cholesterol before changing your intake.

Caloric Surplus vs. Deficit: The Energy Equation

The total number of calories you consume matters as much as the macronutrient proportions. Severe, prolonged calorie deficits are associated with suppressed testosterone. One common explanation is that the body downregulates reproductive hormones when energy is scarce.

In a study of US Army Ranger students, who spent eight weeks with energy deficits averaging 1,000 to 1,200 kcal per day plus sleep loss and heavy workload, testosterone approached about 4.5 nmol/L, and it recovered promptly once the men were refed.^[5] That is an extreme scenario, not a model for everyday dieting, and we do not have good data on exactly how much a moderate deficit lowers testosterone.

For men who are overweight or obese, the picture is reassuring: a systematic review and meta-analysis of 24 studies found that weight loss, through a low-calorie diet or bariatric surgery, was associated with a significant increase in both bound and unbound testosterone.^[6] A moderate deficit (commonly 300 to 500 calories below maintenance) combined with resistance training and adequate protein is a widely used approach for gradual fat loss, though this range is a coaching convention rather than a study-tested threshold. A deeper analysis of this relationship is available in our article on body fat and testosterone.

For lean men who are already at a healthy body composition, eating at maintenance rather than staying in a long deficit is a sensible way to avoid the energy-deficit effects described above.

Meal Timing Around Training

While macronutrient totals matter more than timing for testosterone production, the timing of meals around resistance training can optimize the acute hormonal response and overall recovery.

Pre-training (1-2 hours before): A mixed meal containing carbohydrates, moderate protein, and some fat ensures glycogen stores are adequate and cortisol does not spike excessively during training. Some people find that training fasted or under-fuelled feels worse; a simple option is 40 to 60 grams of carbohydrates with 20 to 30 grams of protein.

Post-training (within 1-2 hours): A meal combining carbohydrates and protein provides amino acids for muscle repair and replenishes glycogen. The carbohydrate-and-training study cited above suggests that eating enough carbohydrate around hard training is associated with a steadier testosterone-to-cortisol ratio.^[10]

Before bed: A meal or snack containing slow-digesting protein (like casein from dairy) and some fat provides sustained amino acid availability during the overnight fasting period. Evidence for bedtime protein is mostly about muscle recovery, so treat this as optional.

A Sample Day of Eating for Testosterone

Below is a sample day of eating for a 180-pound man aiming for approximately 2,800 calories with a macro split of roughly 30 percent fat, 45 percent carbohydrates, and 25 percent protein. This serves as a template, not a prescription. Adjust quantities to match your caloric needs.

Practical Takeaways

Supporting your hormonal health through nutrition does not require obsessive tracking or exotic foods. The principles are straightforward:

1. Keep dietary fat at 25 to 35 percent of calories. Include both saturated and monounsaturated sources. Do not fear eggs, olive oil, nuts, or moderate amounts of red meat, and avoid driving fat very low, even during a cutting phase.

2. Consume adequate carbohydrates, especially around training. Aim for 40 to 50 percent of calories from whole food carbohydrate sources. In the studies above, very low-carbohydrate eating during hard training was associated with a worse testosterone-to-cortisol ratio.

3. Eat enough protein without going overboard. Target 0.7 to 1.0 grams per pound of body weight. Spreading protein across 3 to 4 meals is a common approach for muscle maintenance.

4. Avoid chronic energy deficits. If you need to lose fat, use moderate deficits and consider planned diet breaks. If you are lean, eat at maintenance.

5. Time your meals around training. A pre-training meal with carbs and protein supports performance, and a post-training meal supports recovery.

These are general education points, not medical advice. If you have symptoms such as persistent fatigue, low libido, or unexplained changes in mood or body composition, or if you have a medical condition, talk with a doctor before changing your diet, and ask about proper blood testing.

Related Reading

• How to Increase Testosterone Naturally: where macros sit in the hierarchy of lifestyle habits that support testosterone.
• The Complete T-Maxing Guide: the full habit stack your macros should support.
• Testosterone Supplements That Actually Work: what to consider only once the diet fundamentals are in place, and ideally after speaking with a doctor.

How Thrive Helps

Nutrition is one of the lifestyle pillars associated with hormonal health, and it works best when it is consistent. Thrive tracks your daily nutrition habits alongside sleep, exercise, and stress management, giving you a complete picture of your routines. The scoring system rewards consistency across all pillars, not perfection in any single one. Thrive is a wellness app, not a medical device, and individual results vary.

Try Thrive and build consistent nutritional habits as part of a healthy lifestyle.