Does Sugar Lower Testosterone? What the Research Shows
Sugar and testosterone have a more documented connection than most diet claims. One study measured a clear short-term drop in testosterone after a big glucose dose, and another found that men who drank more sugar-sweetened beverages had higher odds of low testosterone. The long-term picture is less certain, so this article separates what the research shows from what it does not.
Key takeaways
- In a 2013 study of 74 men, a 75 g oral glucose load was followed by a 25% fall in mean testosterone, which stayed suppressed at 120 minutes (13.7 vs 16.5 nmol/L at baseline).[1]
- Of the 66 men with normal baseline testosterone, 10 (15%) dropped into the low range at one or more time points, which is why testing is done fasting.[1]
- In NHANES data on 545 men aged 20 to 39, the highest quartile of sugar-sweetened beverage intake (442 kcal/day or more) had an adjusted odds ratio of 2.29 for low testosterone versus the lowest quartile. This is an association, not proof of cause.[2]
- The American Heart Association suggests most men limit added sugar to about 150 calories a day.[3] This is general education, not medical advice.
The Glucose Study: 75 Grams, 25% Lower Testosterone
Researchers at Massachusetts General Hospital gave 74 men (aged 19 to 74) a standard 75-gram oral glucose tolerance test, the same test used to screen for diabetes, and measured testosterone at 0, 30, 60, 90 and 120 minutes. Glucose ingestion was associated with a 25% decrease in mean testosterone, and levels were still lower at 120 minutes (13.7 versus 16.5 nmol/L). The drop did not differ across glucose tolerance (57% of the men had normal glucose tolerance, 30% impaired, 13% newly diagnosed type 2 diabetes) or body mass index.[1]
Among the 66 men whose baseline testosterone was normal, 10 (15%) fell below the hypogonadal threshold at one or more time points. The authors noted that SHBG, LH and cortisol did not change, and suggested the drop reflects a direct testicular effect plus a possible central component.[1] This was a single-dose, short-term test, so it tells us about the immediate response to a large glucose load and not about everyday eating.
Why This Matters for Testing
The authors concluded that men found to have low non-fasting testosterone should be re-evaluated in the fasting state.[1] The Endocrine Society guideline likewise recommends measuring fasting morning total testosterone and repeating the measurement to confirm a diagnosis.[4]If you are getting tested, follow your doctor's instructions on fasting and timing, and avoid sugary drinks before a blood draw.
Sugar-Sweetened Beverages and Low Testosterone
Beyond the acute test, researchers have looked at habitual intake. A population study using NHANES 2011-2012 data covered 545 men aged 20 to 39. Of these, 59 (9.6%) had low testosterone, defined as under 231 ng/dL. After adjusting for age, race/ethnicity, income, BMI, smoking exposure, heavy drinking and physical activity, men in the highest quartile of sugar-sweetened beverage intake (442 kcal/day or more) had an adjusted odds ratio of 2.29 for low testosterone compared with the lowest quartile (137 kcal/day or less).[2]
The study also found that a BMI of 25 or above was an independent risk factor (adjusted odds ratio 3.68).[2] Because this is a single-time-point survey with a modest number of low-testosterone cases, it cannot show that sugary drinks lower testosterone, only that the two go together. People who drink a lot of sugary beverages may differ in many other ways.
Possible Mechanism: Insulin, Body Fat, and Metabolic Health
When you consume sugar, blood glucose rises and your pancreas releases insulin. Over years, a diet high in sugar and calories can contribute to weight gain and insulin resistance. Metabolic health and testosterone are closely linked: in a study of 103 men with type 2 diabetes, 33% had low free testosterone, and body mass index correlated inversely with free testosterone.[5] Excess body fat (see also belly fat) is therefore a more established route than sugar itself. For more on this relationship, see our guide to testosterone and type 2 diabetes.
✓ Better Choices
- •Whole fruit (fiber slows absorption)
- •Complex carbohydrates (oats, sweet potatoes)
- •Carbohydrates paired with protein
- •Water, black coffee, unsweetened tea
✗ Main Sources to Cut Back
- •Sugary sodas and energy drinks
- •Fruit juice and sweetened coffees
- •Candy, pastries and desserts as a daily habit
- •Hidden sugars in sauces, dressings and yogurts
What About Fructose?
Fructose is a concern in animal research. In a 2022 rat study, animals fed a high-fructose diet for 21 weeks developed high blood sugar and insulin, and had lower plasma testosterone and LH than controls, along with reduced sperm motility.[6] Rats are not men, and the diet was far more extreme than typical human intake, so this is a reason for caution about heavy sugary-drink habits, not proof of an effect in people.
Practical Ways to Cut Back on Added Sugar
The goal is not to eliminate sugar entirely. The American Heart Association's scientific statement recommends reducing added sugars, with a prudent upper limit for most men of no more than 150 calories per day from added sugars (about 36 grams or 9 teaspoons). Soft drinks and other sugar-sweetened beverages were the primary source of added sugars in Americans' diets.[3]
A Gradual 4-Week Approach
Cut back on sugar-sweetened beverages
These are the largest source of added sugar for many people. Swap sodas, sweetened coffees and energy drinks for water, black coffee or unsweetened tea.
Check labels for hidden sugars
Read labels on condiments, sauces, yogurts, granola bars and bread, where added sugars often hide. Choose lower-sugar versions where you can.
Build meals around protein, fiber and whole foods
Meals with protein, fiber and healthy fats tend to be more filling, which can make sweet snacks less tempting.
Settle into a sustainable pattern
Aim for added sugar to be an occasional treat rather than a daily staple, and keep within the American Heart Association guidance above.
This Is About Pattern, Not Elimination
Nothing in this research suggests you need to live sugar-free. The 25% drop in the glucose study followed a single large dose and was measured over two hours. We found no evidence on how long such drops last in daily life, or that occasional sweets affect long-term testosterone. The larger concern is the broader pattern: high sugar intake alongside weight gain, low activity and poor sleep. If you are worried about low testosterone, talk to a doctor about testing instead of trying to fix it through diet alone.
Summary
- A 75 g glucose load was followed by a temporary average 25% fall in testosterone in one study of 74 men.
- Higher intake of sugar-sweetened beverages was associated with higher odds of low testosterone in young US men, but this does not prove cause.
- Excess body fat and type 2 diabetes are well-established companions of lower testosterone, so metabolic health is the bigger lever.
- Cutting back on sugary drinks is a sensible general health step that fits with balanced nutrition, exercise and sleep.
References
- Caronia LM, Dwyer AA, Hayden D, Amati F, Pitteloud N, Hayes FJ. Abrupt decrease in serum testosterone levels after an oral glucose load in men: implications for screening for hypogonadism. Clin Endocrinol (Oxf). 2013. doi.org/10.1111/j.1365-2265.2012.04486.x
- Chen L, Xie YM, Pei JH, et al.. Sugar-sweetened beverage intake and serum testosterone levels in adult males 20-39 years old in the United States. Reprod Biol Endocrinol. 2018. doi.org/10.1186/s12958-018-0378-2
- Johnson RK, Appel LJ, Brands M, et al.. Dietary sugars intake and cardiovascular health: a scientific statement from the American Heart Association. Circulation. 2009. doi.org/10.1161/CIRCULATIONAHA.109.192627
- Bhasin S, Brito JP, Cunningham GR, et al.. Testosterone therapy in men with hypogonadism: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2018. doi.org/10.1210/jc.2018-00229
- Dhindsa S, Prabhakar S, Sethi M, Bandyopadhyay A, Chaudhuri A, Dandona P. Frequent occurrence of hypogonadotropic hypogonadism in type 2 diabetes. J Clin Endocrinol Metab. 2004. doi.org/10.1210/jc.2004-0804
- Hsia SM, Chiang YF, Chen HY, Ali M, Wang PS, Wang KL. Effect of high-fructose diet-induced metabolic syndrome on the pituitary-gonadal axis in male rats. Biomedicines. 2022. doi.org/10.3390/biomedicines10123009
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