From a nutritional perspective, weight loss is entirely dependent on establishing a caloric deficit in order to steer the body’s metabolic functions towards consumption of energy in the form of stored fats. However, there are several factors not related to nutrition that can affect an individual’s ability to lose weight such as various pathologies, and hormonal imbalances.
Several studies have concluded and postulated that hormone replacement therapy comprising of testosterone doses could be conducive to appreciable weight loss in males, even without the presence of an intentional increase to the amount of exercise performed or any drastic alterations to diet. Inversely, weight gain has repeatedly been linked to decreasing levels of serum testosterone. Today we will be discussing how these processes affect female to male transgender patients. How does masculinizing testosterone therapy affect them FtM patients in terms of weight loss and body composition?
EFFECTS OF TESTOSTERONE ON WEIGHT LOSS
It is widely known that testosterone is heavily involved in biological and metabolic processes that are responsible for the growth of lean muscle mass and sexual function. Few people know, however, that testosterone is also a potent aid in the fight against obesity as can be evidenced in the fact that men with low testosterone levels are significantly more susceptible to rapid and unnatural weight gain.
Testosterone plays an essential role in the growth and development of the human male and to a lesser degree the human female. Testosterone activation is carried out through two distinct methods of action. Some of the specific effects of testosterone action include:
Androgenic effects of testosterone – The maturation of sexual organs such as the penis and testes in males is mediated by testosterone action in the womb and later during puberty. Secondary sexual characteristics are also governed by testosterone action; these include the growth of facial, pubic, axillary hair, and a deepening of the voice.
Anabolic effects of testosterone – Testosterone triggers potent anabolic effects and as such is considered an anabolic steroid. Testosterone stimulates the growth of muscle mass, the density of bones, and the development of strength.
Androgenic receptors in the body selectively receive metabolic pathway signals and activate the following effects:
- Testosterone leads to a higher density of androgenic receptors in fat cells.
- Testosterone also helps block specific corticosteroid receptors of the hormone cortisol; which is a hormone that promotes the loss of muscle mass.
- Testosterone has many other complex actions in the body at the cellular level. It works in synergy with other hormones in the body, such as Human Growth Hormone, and stimulates the body into losing fat.
- Testosterone is also naturally converted to estrogen and DHT; together, these two hormones also have anti-lipolytic properties.
- Testosterone does not inherently induce fat loss per say; what really occurs is that testosterone helps to regulate the synthesis of fats.
MASCULINIZATION OF FEMALES TAKING TESTOSTERONE
An interesting effect occurs in females undergoing testosterone hormone replacement therapy in lieu of a gender reassignment process.
Female to Male hormone replacement therapy or HRT for short is a type of hormone replacement therapy that is applied in order to change the secondary sexual characteristics of transgender and transsexual people from feminine to masculine.
This type of HRT causes the development of masculine secondary sex characteristics in transgender females. The induced secondary sexual characteristics include a deepening of the gradual development of a masculine hair pattern, and a more masculine fat and muscle distribution. It is important to note that these types of hormone replacement therapies do not undo or revert the changes induced during puberty such as the development of breast tissue; the alteration of these usually requires surgical intervention. As with other patients who undergo any type of exogenous hormone therapy, FtM patients report changes at every level of the body such as energy levels, a variability of moods, and increased appetite.
FtM patients experience a mix of reversible and irreversible changes that include but are not limited to:
- A deepening of the voice
- The growth of facial hair
- Increased sexual appetite
- Enlargement of the clitoris
- Cessation of menstruation
- Alterations of blood chemistry such as increased levels of serum cholesterol and triglycerides
- Increased in musculature
- Redistribution of body fat
DOES THE FtM PROCESS HELP WITH WEIGHT LOSS
Testosterone therapy normally causes an increase in body weight as well as a marked increase in an individual’s appetite levels. As body composition changes and fat deposits undergo a physiological shift, the exact form that the expected weight gain takes will depend to a great degree on the type of diet consumed and the amount and intensity of any exercise performed; additionally, genetic factors will play significant roles.
Unquestionably, because of testosterone’s pronounced anabolic effects, the average FtM patient experiences an increase to lean muscle mass. If the FtM patient exercises moderately even greater gains will be achieved. Consequently, a higher proportion of musculature to fat is directly proportional to having a higher metabolic expenditure, and as such the FtM patient can experience some form of weight loss.
THE BOTTOM LINE
The human body follows certain metabolic rules that do not differ between genders. In this case, there is no assessable difference in the mechanisms that regulate weight loss between males and females. When a male patient or an FtM patient attempts to lose weight, for the most part, it will simply come down to burning more calories than those that are consumed on a daily basis. Because caloric intake is primarily dependent on dietary constraints, weight loss progress will be primarily affected by the foods consumed and the exercise performed.
However, many transgender men who have undergone testosterone hormone replacement therapy have reported increased levels of energy as well as increased alertness. This can make working out on a consistent basis much easier to achieve. Testosterone’s anabolic action will also make FtM patients have much-shortened recovery time between workouts. That, in conjunction with the increased energy and alertness, can most definitely be conducive to quantifiable weight loss.
- Perrone, Anna Myriam, et al. “Effect of Long‐Term Testosterone Administration on the Endometrium of Female‐to‐Male (FtM) Transsexuals.” The journal of sexual medicine 6.11 (2009): 3193-3200.
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- Karila, T. A. M., et al. “Rapid weight loss decreases serum testosterone.” International journal of sports medicine 29.11 (2008): 872-877.
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- Rhoden, Ernani Luis, and Abraham Morgentaler. “Risks of testosterone-replacement therapy and recommendations for monitoring.” New England Journal of Medicine 350.5 (2004): 482-492.