Testosterone and Weight Loss

Testosterone and weight loss are not the first thing that is thought of by the average person who is either considering losing weight or gaining weight. Testosterone is a major hormone in the human body that is produced in abundance in males. The testicles are the primary site of production for testosterone in males; for women, testosterone is produced in smaller amounts in the ovaries and adrenal glands as well (Santen, 1975). The relationship between testosterone and weight loss is not as cut and dried as drawing a simple line from point A to point B. In fact, like most hormones of the human body, the impact of hormones on body systems involves a complex set of interactions with other chemical messengers that, when working correctly, help the body achieve homeostasis, or balance of body systems (Mazzoccoli, 2011). This article helps the reader understand how testosterone and weight loss are related, and explains how testosterone and weight loss may impact overall health functioning.

Testosterone - the Miracle Grow Hormone

Testosterone levels are an order of 10 times higher in men than women (Jockenhovel, 2004). Not surprising that a man's muscle mass is therefore 60% to 80% higher than a woman's muscle mass (Folland & William, 2007). Testosterone is responsible for normal reproductive development, and is involved in developing muscle mass, hair growth (or lack of), height, and a deepened voice. Testosterone and weight loss are not necessarily related at the level of the simple idea if I take away testosterone, will I lose weight or if I take testosterone replacements, will I gain weight. Testosterone is the hormone in the body responsible for growth and normal sexual development, yet testosterone and weight loss do not exist in a direct causal relationship (Strohmayer, Via, & Yanagisawa, 2010).

Testosterone and Weight Loss - Medical Conditions

In order to understand the relationship between testosterone and weight loss, we can look at medical conditions to illustrate the concept. Remember we said that testosterone is the major growth hormone in the body, this is specific to growth of sexual characteristics, including muscle mass. Testosterone does not increase one's adipose (fat) tissue, however, and should not be construed to mean that more testosterone means more body fat; as a matter of fact, a rise in body fat signals a decrease in testosterone levels (Guay & Traish, 2011). Testosterone and weight loss can be thought of in two major categories: addition of body fat, and loss of muscle mass. Additionally, a loss of muscle mass can mean that clinically low levels of testosterone are manifesting; this could indicate sarcopenia and/or hypogonadism (Bain, 2010). But what should you do? Let's explore these conditions to find out more about testosterone and weight loss.

Medical Condition #1: Obesity

Obesity is defined as having a body mass index (BMI) of 30 or greater. BMI really only tells us the approximated ratio of muscle mass to body fat, given a person's height and weight. For a true body muscle mass to fat ratio, other methods should be used. However, for these purposes we will consider that a BMI over 30 indicates the medical condition of obesity. So what is the relationship between testosterone and weight loss when a person has the medical condition of obesity?

Guay and Traish (2011) stated that metabolic syndrome, which includes excessive adipose tissue in the abdomen, has testosterone deficiency as an underlying condition, with a further underlying condition of that being insulin resistance. Meaning, insulin resistance is one factor involved in testosterone and weight loss (and gain). In a study on erectile dysfunction due to metabolic syndrome, Guay and Traish (2011) found that testosterone deficiency underlies endothelial dysfunction (a core symptom of erectile dysfunction) and metabolic syndrome, with the key culprit being insulin resistance. So what is the relationship between testosterone and weight loss, and obesity? Insulin resistance. To put it simply, insulin resistance causes an imbalance in glucose metabolism, contributing to fat storage on the body. But how are insulin and testosterone related, and why is this important to testosterone and weight loss?

The story begins in the brain, where the master endocrine gland, the pituitary gland, secretes a messenger chemical to tell the testes to make more testosterone. The messenger chemical is called luteinizing hormone (LH) (Santen, 1975). The following diagram offers a visual guide:

To illustrate the testosterone production cycle, the following diagram is offered:

If for some reason either pituitary output of LH is impaired, or LH receptors in the testes are dysfunctional, less testosterone will be produced. Low circulating testosterone contributes to insulin resistance, likely due to decreased glucose metabolism (Mohlig, et al., 2011). Testosterone and weight loss, and weight gain, are linked through the mechanism of insulin resistance and glucose metabolism. And that begins the next discussion on testosterone and weight loss, and muscle mass.

Medical Condition #2: Sarcopenia

Sarcopenia literally means poverty of the flesh and is where a person progressively loses muscle mass, due to factors usually associated with aging (Boirie, 2009). Muscle mass is replaced with fat tissue, due to cellular level changes in the muscles. These changes are most often related to aging, where testosterone levels fall as a natural consequence of the aging process as well. When a man ages, and testosterone levels fall, age-induced Hypogonadism results; this is simply clinically low testosterone levels. Hypogonadism contributes to sarcopenia, and testosterone and weight loss are related in this manner in terms of the loss of muscle mass and the potential increase of fat tissue. Hypogonadism does not only affect the maturing population of adult men; when Hypogonadism affects younger men, sarcopenia can also result (Bain, 2010).

The reasons for clinically low testosterone levels may be varied and should be discussed with your doctor; these factors may be genetic, they may be environmental, or they may be age-related. Diet and nutrition are important factors to consider as well, as it is important to ensure the body is getting everything it needs to support normal endocrine and hence testosterone function.

The important part to remember about testosterone and weight loss is that low circulating testosterone levels contribute to insulin resistance, which leads to decreased glucose metabolism; all this can mean a decrease in lean muscle mass and an increase in adipose tissue.

Testosterone and Weight Loss: Should I Consider Testosterone Replacement Therapy?

The general medical consensus is that testosterone replacement therapy helps alleviate symptoms of Hypogonadism, or more simply, low testosterone levels. In turn, this can help mitigate problems associated with testosterone and weight loss, such as loss of lean muscle mass, increase in fat tissue, increased insulin resistance, and decreased glucose metabolism (Mohlig, et al., 2011).

However, it should be noted that there is a dark side to testosterone replacement therapy and weight loss, one that people should sit up and take notice of. Some people may think that taking testosterone supplementation can help them lose weight. On its face, it seems to make sense, after all, if testosterone can increase muscle mass and more muscle mass burns more calories than fat cells do, would a person not lose weight? The answer is an emphatic "no". A case study example illustrates the problem: a 33 year old bodybuilder was taking androgenic anabolic steroids to increase muscle mass and lose weight. What ended up happening is the combination of testosterone supplements with the other hormones caused a critical glucose metabolism decrease, and increased insulin resistance. The man was diagnosed with new-onset diabetes, which did not resolve once he stopped taking the supplements (Geraci, Cole, & Davis, 2011). The message and caution is that unless you have been prescribed testosterone replacement, do not take testosterone for weight loss issues without a full clinical evaluation by a licensed medical practitioner.

Summary

The main points here are that testosterone and weight loss are related in a complex body system management schema, that low testosterone can impact insulin and glucose which can lead to weight gain through loss of muscle mass, and that testosterone and weight loss cannot simply be managed through testosterone supplementation. If you are experiencing decreased muscle mass, or are obese and concerned about your testosterone levels, see your doctor. Together you can work out a treatment plan that is designed for you.

References

Bain, J. (2010). Testosterone and the aging male: to treat or not to treat? Maturitas, 66(1), 16-22.

Baum, N., & Crespi, C. (2007). Testosterone replacement in elderly men. Geriatrics, 62(9), 15-18.

Boirie, Y. (2009). Physiopathological mechanism of sarcopenia. The Journal of Nutrition, Health & Aging, 13(8), 717-723.

Folland, J., & William, A. (2007). The adaptations to strength training : morphological and neurological contributions to increased strength. Sports Medicine, 37(2), 145-168.

Geraci, M., Cole, M., & Davis, P. (2011). New onset diabetes associated with bovine growth hormone and testosterone abuse in a young body builder. Human & Experimental Toxicology, doi: 10.1177/0960327111408152.

Geraci, M., Cole, M., & Davis, P. (2011). New onset diabetes associated with bovine growth hormone and testosterone abuse in a young body builder. Human & Experimental Toxicology, doi: 10.1177/0960327111408152.

Guay, A., & Traish, A. (2011). Testosterone deficiency and risk factors in the metabolic syndrome: implications for erectile dysfunction. The Urologic Clinics of North America, 38(2), 175-183.

Jockenhovel, F. (2004). Testosterone therapy--what, when and to whom? Aging Male, 7(4), 319-324.

Mazzoccoli, G. (2011). The timing clockwork of life. The Journal of Biological Regulators and Homeostatic Agents, 25(1), 137-143.

Mohlig, M., Arafat, A., Osterhoff, M., Isken, F., Weickert, M., Spranger, J., et al. (2011). Androgen receptor CAG repeat length polymorphism modifies the impact of testosterone on insulin sensitivity in men. European Journal of Endocrinology, 164(6), 1013-1018.

Myers, J., & Meacham, R. (2003). Androgen replacement therapy in the aging male. Reviews in Urology, 5(4), 216-226.

Santen, R. (1975). Is aromatization of testosterone to estradiol required for inhibition of luteinizing hormone secretion in men? Journal of Clinical Investigation, 56(6), 1555-1563.

Strohmayer, E., Via, M., & Yanagisawa, R. (2010). Metabolic management following bariatric surgery. Mt. Sinai Journal of Medicine, 77(5), 431-445.