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Young Men, Waist, Testosterone and Erectile Function: Low-T is not only an old man's issue

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Most people, including traditional doctors, think that testosterone deficiency is an old man’s issue. This is very wrong! Actually, an excess amount of body fat can cause a man’s testosterone levels drop to as much as 10 years of aging.[1]
Several studies have demonstrated that too much body fat is associated with reduced testosterone levels independent of aging.[2-4]
Low levels of testosterone (both total and free testosterone) are a consistent feature among young men below 40 years of age with metabolic syndrome, the hallmark of which is an enlarged belly.[5]
Young men (20–39 years) with the lowest baseline total testosterone levels have the highest risk of developing cholesterol and blood fat abnormalities (dyslipidemia). [6] Compared to age-matched men with the highest baseline total testosterone levels of 663 ng/dL or higher, those with the lowest baseline total testosterone levels of 418 ng/dL or below had up to a twofold greater risk of developing an adverse lipid profile 5 years later, which in turn could contribute to future risk of cardiovascular disease.[6]
Thus, testosterone deficiency clearly has health implications also for younger men. But how much does your belly actually impact your testosterone levels… and erectile function?

How is your waist related to your testosterone levels?

A commonly used cut-off to “diagnose” abdominal obesity in men is a waist circumference of 40 in. Several studies have shown that belly fat (i.e. abdominal obesity) is inversely associated with testosterone levels in men, i.e. the larger a man’s waist circumference the lower his testosterone level.[7-13] The reduction in testosterone with expanding bellies is especially marked for the free “active” testosterone fraction.[7, 11, 12] 
An interesting study of 1528 men aged 25-84 years showed how testosterone levels vary by waist circumference, age and BMI (a proxy for obesity).[14] Men with a waist of 40 in (102 cm) had a significantly lower total testosterone level compared to men with an optimal waist, defined as 37 in (94 cm) or less, even after adjusting for age and BMI.[14] Also, regardless of age, men with larger bellies had a significantly lower free testosterone level. Table 1 summarized how testosterone levels were related to waist in each age group.
Table 1: Total and free testosterone levels by waist circumference in men aged 25–84 years.[14]






Waist circumference


37in (94 cm) or less


40 in (102 cm) or more

Total testosterone

ng/dL (nmol/L)











450 (15.6)

450 (15.6)

415 (14.4)

430 (14.9)

404 (14)





320 (11.1)

294 (10.2)

320 (11.1)

320 (11.1)

309 (10.7)

Free testosterone

pg/mL (pmol)











105 (302)

93 (268)

77 (221)

68 (196)

59 (171)






98 (282)

77 (222)

72 (207)

66 (190)

58 (166)


Note that the reference range for total testosterone of the used assay is 200-800, which is why the testosterone levels in the table (especially in young men) may seem low. The difference in total testosterone for a 25-39 year old man with a waist of 37 in compared to a same age man with a waist of 40 in is 130 ng/dL with this assay. For analytical assays with wider reference ranges and higher values for the upper end of the reference range the difference would be larger, possibly in the range of 260-360 ng/dL.
As seen in table 1, there is a greater reduction in free testosterone than total testosterone with aging. This finding is well documented [15-17], and should be kept in mind if only total testosterone levels are measured as part of the diagnosis of testosterone deficiency, as that may mask a deficiency in free testosterone in older men.
What’s especially notable with this study is that the lowest levels of total and free testosterone were observed in non-obese young men with the highest waist circumference.[14] This is good news because an enlarged waist is a modifiable risk factor. Young men, by adhering to healthy food choices and regular exercise can naturally increase their testosterone levels, physical attractiveness, libido and… erectile function.

Young men and erectile function…

It is well documented that erectile dysfunction is a common complaint in men over 40 years of age, and that prevalence of erectile dysfunction increase throughout the aging period.[18] However, prevalence and risk factors of erectile dysfunction among young men have not received much attention. A study that specifically investigated this found that 1 of 4 men seeking first medical help for new onset erectile dysfunction is a young man (below 40 years old). Almost half of the young men suffered from severe erectile dysfunction, with comparable rates in older patients.[19]
It should be noted that erectile dysfunction is a multifactorial issue.[18] Nevertheless, a large waist and its associated reduction in testosterone levels – both of which are hallmarks of the metabolic syndrome – are likely strong contributing factors to erectile dysfunction, even among young men.[5, 20]

Exercise as a waist trimmer and…. sex booster!

Studies have shown an association between erectile dysfunction and sedentary lifestyle in middle-aged men, with a direct correlation between increased physical activity and improved erectile function.[21-23] An interesting study examined the association between sedentariness / exercise and erectile function in young, healthy men between the ages of 18 and 40 years old.[24] A sedentary lifestyle was associated with reduced erectile function, orgasm, intercourse satisfaction and overall sexual satisfaction, when compared to young men who exercised regularly. Increased physical activity was associated with better sexual function in young men.[24]


A man’s belly – regardless of his age – is a “vital sign” that reflects testosterone levels, and possibly erectile function and sexual satisfaction (for himself as well as his partner). Take home message for all men; if you don’t feel like going to the gym, remind yourself about this. 
See exercise – and by exercise I mean both weight lifting AND cardio – as a waist trimmer and sex booster. Break a sweat in the gym and you will be rewarded manifold!


1.            Travison, T.G., et al., The relative contributions of aging, health, and lifestyle factors to serum testosterone decline in men. J Clin Endocrinol Metab, 2007. 92(2): p. 549-55.

2.            Muller, M., et al., Endogenous sex hormones in men aged 40-80 years. Eur J Endocrinol, 2003. 149(6): p. 583-9.

3.            Wu, F.C., et al., Hypothalamic-pituitary-testicular axis disruptions in older men are differentially linked to age and modifiable risk factors: the European Male Aging Study. J Clin Endocrinol Metab, 2008. 93(7): p. 2737-45.

4.            Zumoff, B., et al., Plasma free and non-sex-hormone-binding-globulin-bound testosterone are decreased in obese men in proportion to their degree of obesity. J Clin Endocrinol Metab, 1990. 71(4): p. 929-31.

5.            Goncharov, N.P., et al., Three definitions of metabolic syndrome applied to a sample of young obese men and their relation with plasma testosterone. Aging Male, 2008. 11(3): p. 118-22.

6.            Haring, R., et al., Prospective association of low total testosterone concentrations with an adverse lipid profile and increased incident dyslipidemia. Eur J Cardiovasc Prev Rehabil, 2011. 18(1): p. 86-96.

7.            Seidell, J.C., et al., Visceral fat accumulation in men is positively associated with insulin, glucose, and C-peptide levels, but negatively with testosterone levels. Metabolism, 1990. 39(9): p. 897-901.

8.            Pasquali, R., et al., Effect of obesity and body fat distribution on sex hormones and insulin in men. Metabolism, 1991. 40(1): p. 101-4.

9.            Tchernof, A., et al., Reduced testosterone and adrenal C19 steroid levels in obese men. Metabolism, 1995. 44(4): p. 513-9.

10.          Couillard, C., et al., Contribution of body fatness and adipose tissue distribution to the age variation in plasma steroid hormone concentrations in men: the HERITAGE Family Study. J Clin Endocrinol Metab, 2000. 85(3): p. 1026-31.

11.          Abate, N., et al., Sex steroid hormones, upper body obesity, and insulin resistance. J Clin Endocrinol Metab, 2002. 87(10): p. 4522-7.

12.          Haffner, S.M., et al., Obesity, body fat distribution and sex hormones in men. Int J Obes Relat Metab Disord, 1993. 17(11): p. 643-9.

13.          Khaw, K.T. and E. Barrett-Connor, Lower endogenous androgens predict central adiposity in men. Ann Epidemiol, 1992. 2(5): p. 675-82.

14.          Svartberg, J., et al., Waist circumference and testosterone levels in community dwelling men. The Tromso study. Eur J Epidemiol, 2004. 19(7): p. 657-63.

15.          Feldman, H.A., et al., Age trends in the level of serum testosterone and other hormones in middle-aged men: longitudinal results from the Massachusetts male aging study. J Clin Endocrinol Metab, 2002. 87(2): p. 589-98.

16.          Camacho, E.M., et al., Age-associated changes in hypothalamic-pituitary-testicular function in middle-aged and older men are modified by weight change and lifestyle factors: longitudinal results from the European Male Ageing Study. Eur J Endocrinol, 2013. 168(3): p. 445-55.

17.          Liu, P.Y., et al., Age-related changes in serum testosterone and sex hormone binding globulin in Australian men: longitudinal analyses of two geographically separate regional cohorts. J Clin Endocrinol Metab, 2007. 92(9): p. 3599-603.

18.          Salonia, A., et al., Is erectile dysfunction a reliable indicator of general health status in men? Arab J Urol, 2013. 11(3): p. 203-11.

19.          Capogrosso, P., et al., One patient out of four with newly diagnosed erectile dysfunction is a young man--worrisome picture from the everyday clinical practice. J Sex Med, 2013. 10(7): p. 1833-41.

20.          Kaya, E., S.C. Sikka, and S. Gur, A comprehensive review of metabolic syndrome affecting erectile dysfunction. J Sex Med, 2015. 12(4): p. 856-75.

21.          Bacon, C.G., et al., Sexual function in men older than 50 years of age: results from the health professionals follow-up study. Ann Intern Med, 2003. 139(3): p. 161-8.

22.          DeLay, K.J., N. Haney, and W.J. Hellstrom, Modifying Risk Factors in the Management of Erectile Dysfunction: A Review. World J Mens Health, 2016. 34(2): p. 89-100.

23.          Lamina, S., E. Agbanusi, and R.C. Nwacha, Effects of aerobic exercise in the management of erectile dysfunction: a meta analysis study on randomized controlled trials. Ethiop J Health Sci, 2011. 21(3): p. 195-201.

24.          Hsiao, W., et al., Exercise is associated with better erectile function in men under 40 as evaluated by the International Index of Erectile Function. J Sex Med, 2012. 9(2): p. 524-30.



Last modified on Wednesday, 21 September 2016 00:11

Medical Writer & Nutritionist

MSc Nutrition

University of Stockholm & Karolinska Institute, Sweden 

   Baylor University, TX, USA

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