It was reported by Doctors Data in the US that more than two thirds of American adults are overweight or obese and there is no reason to think the UK is not far behind.
As our waistline increases so does insulin resistance, metabolic syndrome and type 2 diabetes and the link between decreasing testosterone levels associated with these syndromes is well established in the scientific literature.
For example: men with diabetes have significantly lower levels of serum testosterone when compared with men without diabetes; and men in the lowest level of free testosterone have a four-fold increased risk of having diabetes when compared with men in the highest level of free testosterone.
The mechanisms as to the link between insulin resistance and low testosterone are still being established: low sex hormone binding globulin (SHBG) is associated with a higher risk of type 2 diabetes in men and women and is a strong predictor of diabetes.
Obesity also plays a role where the enzyme aromatase can convert testosterone into estradiol, thus diminishing testosterone levels.
Testosterone and sugar
A 2013 study suggests that another mechanism may have a direct impact on testosterone levels: sugar consumption.
A cross-sectional study by Caronia et al. on 74 men between the ages of 19-34 examined the physiological impact of a 75g glucose load on serum total and free testosterone levels in men with varying glucose tolerance. Glucose ingestion was associated with a 25% decrease in mean T levels regardless of GT or BMI, and remained suppressed for 120 minutes.
What is 75g of glucose equivalent to in real food terms? A can of Coca Cola has 75g, a McDonald’s M&M McFlurry has 84.8g, a cup of low-fat fruit yogurt has 46.7g, and a pumpkin spice latte (grande) has 50g of sugar.
It’s easy to see how regular sugar consumption alone can add up to perpetually suppressed testosterone levels in men.+
Could intermittent fasting help?
Interestingly, while testosterone levels fluctuate throughout the day, the authors found levels to be at their highest during fasting states, particularly in the morning.
This information suggests that intermittent fasting, or at least limiting food consumption to three meals per day, in combination with dietary sugar reduction, can play an influential role in increasing or maintaining testosterone levels in men.
Flegal, K.M., Carroll, M.D., Ogden, C.L.et al. (2010) Prevalence and trends in obesity among US adults, 1999–2008. JAMA: the Journal of the American Medical Association 303, 235 –241.
Pitteloud, N., Mootha, V.K., Dwyer, A.A. et al. (2005) Relationship between testosterone levels, insulin sensitivity, and mitochondrial function in men. Diabetes Care, 28, 1636–1642.
Ding EL, Song Y, Malik VS, Liu S. Sex differences of endogenous sex hormones and risk of type 2 diabetes: a systematic review and meta-analysis. JAMA. 2006;295:1288–1299.
Selvin E, Feinleib M, Zhang L, et al. Androgens and diabetes in men: results from the Third National Health and Nutrition Examination Survey (NHANES III) Diabetes Care. 2007;30:234–238.
Beatrice AM, Dutta D, Kumar M, et al. Testosterone levels and type 2 diabetes in men: current knowledge and clinical implications. Diabetes Metab Syndr Obes. 2014;7:481-6. Published 2014 Oct 20. doi:10.2147/DMSO.S50777
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;78(2):291-6
While women are very aware of the risks of oestrogen dominance, very few men realise it also applies to them to. Existing student in Man has been linked to increased risks for prostate and of course the notorious “man boobs“.
As unfortunately men tend not to pay as much attention to their health as women do, if you know someone you feel this might be helpful for please do pass it on.
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