“Dietary deficiency of added sugar intake increases testosterone levels in men.”

Glucose ingestion was associated with a 25% decrease in mean T levels (delta = -4·2 ± 0·3 nm, P < 0·0001). Glucose ingestion induces a significant reduction in total and free T levels in men, which is similar across the spectrum of glucose tolerance.

Multivariate logistic regression analysis revealed that the odds of a low testosterone level was significantly increased with increasing SSB consumption (Q4 (442 kcal/day) vs. Q1 (≤137 kcal/day), adjusted odds ratio [aOR] = 2.29, p = 0.041). Consumption of SSBs is significantly associated with low serum testosterone levels in men 20–39 years old.

Moderate-protein (<35%), low-carbohydrate diets had no consistent effect on resting total testosterone, however high-protein (≥35%), low-carbohydrate diets greatly decreased resting (-1.08 [-1.67, -0.48], p < 0.01) and post-exercise total testosterone (-1.01 [-2, -0.01] p = 0.05). Low- versus high-carbohydrate diets resulted in much higher post-exercise cortisol.

This systematic review examines the effect that manipulating energy and nutrient intake has on circulating concentrations of testosterone, synthesizing evidence on how dietary modifications influence testosterone levels in men.

Acute glucose ingestion is associated with hyperinsulinemia and inflammatory cytokine release, which may contribute to transient reductions in circulating testosterone of approximately 20–30%. Chronic high-sugar intake, particularly from sugar-sweetened beverages, promotes oxidative stress, adiposity, insulin resistance, and leptin dysregulation, which may collectively impair Leydig cell steroidogenesis and contribute to testosterone suppression. After multivariate adjustment, men in the highest quartile of SSB consumption (≥ 442 kcal/day) had significantly higher odds of low serum testosterone (aOR = 2.29, p = 0.041).

The study, published in the journal Clinical Endocrinology, shows that 75g of sugar intake causes a 25 per cent drop in testosterone levels for up to two hours after consumption. Glucose consumption was associated with a 25 per cent decrease in testosterone levels, which remained suppressed at 120 min compared with baseline.

The authors found that the glucose solution decreased blood levels of testosterone by as much as 25 percent, regardless of whether the men had diabetes, prediabetes or normal glucose tolerance. Two hours after glucose administration, the testosterone level remained much lower than before the test in 73 of the 74 men.

A University of Miami study using NHANES data (2003–2004) from 191 men aged 18–75 found that diet type—whether animal-based, healthy plant-based, or unhealthy plant-based—did not significantly affect testosterone levels. The study defined testosterone deficiency as ≤300 ng/dL per the American Urological Association. Author Manish Kuchakulla stated: 'It does not matter if a man eats a diet high in animal foods, a healthy plant-based diet, or a less healthy plant-based diet. We found no difference.'

A study from Osaka Metropolitan University found that testosterone deficiency combined with fructose intake causes changes in gut microbiota that can rapidly worsen fatty liver disease in mice. The research, published in the American Journal of Physiology-Endocrinology and Metabolism, showed that male mice with low testosterone levels accumulated hepatic triglycerides much faster when consuming sugar compared to mice with normal testosterone levels.

Research from the Baltimore Longitudinal Study of Aging (BLSA) shows that the proportion of men with testosterone levels below the reference threshold is approximately 20% in their 60s, 30% in their 70s, and 50% in those 80 and older. The study indicates that men with low testosterone who consume high amounts of sugar accumulate hepatic triglycerides much faster than men with normal testosterone levels.

Another recent review of studies found a link between high calorie, high sugar diets and lower testosterone levels in men.

Research from the UK Medical Research Council's London Institute of Medical Sciences found that high-sugar diets have negative health impacts independent of obesity, suggesting systemic metabolic harm from excessive sugar consumption.

Analysis of 23,245 person-observations from the Whitehall II study using random effects regression found that men in the highest tertile of sugar intake from sweet foods and beverages had a 23% increased odds of incident common mental disorder after 5 years (95% CI: 1.02, 1.48), independent of health behaviours, socio-demographic factors, diet-related factors, adiposity and other diseases.

Testosterone levels dramatically decrease almost immediately after sugar consumption due to the rapid release of insulin in the body. High sugar intake lowers testosterone even in young healthy males according to USA research from 2018. Another study from 2013 demonstrated that oral glucose ingestion by adult males led to an abrupt drop in levels of total and free testosterone.

Recent research has found that the intake of sugar-sweetened beverages (SSB) is associated with low serum testosterone levels among men aged 20–39 years of age. Those men who consumed the largest quantity of sugary beverages each day (442 kcal/day or more) were 2.3 times more likely to have low testosterone compared with those who consumed 137 kcal/day or less.

No high-quality studies show that reducing added sugar intake (lowering it from high levels) increases testosterone levels in men; acute glucose loads cause transient drops, and chronic high sugar is associated with lower levels via insulin resistance and obesity, but low-sugar diets alone do not consistently raise testosterone without other interventions like weight loss.

Research indicates that refined carbohydrates such as white flour and sugar cause rapid blood glucose spikes that promote insulin secretion. When insulin secretion increases in the body, it affects the synthesis of sex hormone precursors, which can reduce attractiveness. This suggests that high-sugar diets negatively impact sex hormone-related physiological processes.

Dr. Kameini Ali of the Westchester County Medical Society states: 'A diet composed mainly of ultra-processed foods affects testosterone levels.' Ultra-processed foods contain added sugars, sodium, and food additives that impact the endocrine system. The article also notes that high-dose curcumin supplements (not typical dietary turmeric) may reduce testosterone in some studies.

Dr. Molly reports that testosterone levels in American men decline by approximately 1% per year after age 30, with 5% of men in their 40s and up to 70% of men in their 70s having testosterone levels below normal range. The article discusses age-related testosterone decline but does not address the relationship between added sugar restriction and testosterone elevation.