Testosterone & Weight Gain in Men
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Does Low Testosterone Cause Weight Gain?
Yes, low testosterone may contribute to weight gain in some men. Testosterone plays a central role in maintaining lean muscle mass, regulating fat distribution, supporting metabolic function, and sustaining energy levels.
When hormone levels fall below the normal range, these processes can be disrupted. This disruption can make it easier to gain weight and harder to lose it.
Why does low testosterone cause weight gain? Testosterone influences several physiological processes that can affect body composition and weight regulation:
- How efficiently the body burns calories
- Where fat is stored
- How effectively muscle is built
- How motivated a person feels to stay active
When any of these are compromised, the conditions for excessive fat gain can take hold.
How Testosterone Affects Body Composition
Testosterone influences body composition through several interconnected mechanisms.
Testosterone binds to androgen receptors in muscle tissue, triggering protein synthesis and supporting muscle growth and maintenance. Because lean muscle burns more calories at rest than fat tissue, any reduction in muscle mass may contribute to a lower basal metabolic rate.
This means the body expends fewer calories throughout the day, even without any change in diet or activity. Consuming excess calories on top of a slower metabolism can make fat gain more likely over time.
Testosterone influences where fat cells are deposited in the body and helps accelerate the breakdown of visceral fat (the fat that surrounds vital organs in the abdomen).
When testosterone levels decline, fat storage can increase, and fat redistribution tends to shift towards the abdomen. Beyond appearance, this has implications for cardiovascular health: excess visceral fat is associated with a higher risk of heart disease and metabolic complications.
Low testosterone has been linked to reduced insulin sensitivity. Poor insulin function can impair the body’s ability to regulate glucose levels effectively, which may further promote fat storage and contribute to difficulties with weight management.
Addressing hormonal imbalances may, in some cases, help the body manage blood sugar and weight more effectively. This varies from person to person and should not be taken as a general rule.
Normal testosterone levels are generally associated with higher energy, better mood, and greater motivation to stay active. Low testosterone can contribute to fatigue and reduced drive, making regular exercise harder to sustain and compounding the impact on body composition over time.
How Body Fat Can Affect Testosterone Levels
30% Lower Testosterone
Research has found that men living with obesity have, on average, around 30% lower total testosterone levels than men within a healthy weight range.
Large population studies, including the European Male Ageing Study, have shown a clear association between increasing body fat and lower testosterone levels.
70%+ of Men with Severe Obesity May Have Testosterone Deficiency
Research suggests that more than 70% of men with Class III obesity (BMI of 40 or above) may have testosterone levels within the deficient range, a condition known as hypogonadism (low testosterone production). One reason for this is that excess body fat can alter hormone balance and increase the conversion of testosterone into oestrogen.
The relationship between weight gain and testosterone works both ways:
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Low testosterone may contribute to increased body fat and reduced muscle mass
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Excess body fat can also be associated with lower testosterone levels
This can create a cycle that becomes increasingly difficult to break without addressing both factors.
Signs & Symptoms of Low Testosterone Weight Gain
Men with low testosterone may notice a range of symptoms alongside changes in weight and body composition. Clinical guidelines identify the following as recognised signs of androgen deficiency:
- Increased body fat, particularly around the abdomen
- Reduced lean muscle mass and strength
- Persistent fatigue and low energy
- Reduced motivation and drive
- Mood changes, including low mood or irritability
- Reduced body hair growth
- Water retention, particularly in the early stages of treatment
- Gradual loss of bone strength and reduced bone mineral density
As these can overlap, a proper clinical assessment is important before making a conclusion.
What To Do Next
If you are concerned about low testosterone or unexplained weight changes, a consultation with a qualified healthcare professional is a suitable first step. A GP or specialist can assess your symptoms, check hormone levels through appropriate blood tests, and discuss the most suitable course of action.
Lifestyle changes that may support healthy testosterone levels and weight management include:
- Maintaining a normal weight through proper nutrition and regular activity
- Resistance and aerobic exercise to preserve lean muscle and promote weight loss
- Getting enough sleep. Research found that restricting sleep to fewer than five hours per night for one week significantly reduced daytime testosterone levels in healthy young men
- Effective stress management to help control cortisol, which can negatively affect hormone balance
- A balanced diet that supports healthy glucose levels and avoids excessive calorie intake
These measures are unlikely to be a complete solution when a clinical testosterone deficiency is present, but they can play a meaningful supporting role alongside any medical treatment and help lower the risk of further complications, including those affecting the cardiovascular system.
Frequently Asked Questions
Yes, low testosterone can contribute to weight gain in some men. It does so by:
Reducing lean muscle mass
Slowing metabolism
Impairing insulin sensitivity
Increasing fat storage
Lowering the energy and motivation needed to stay active.
That said, weight gain has many potential causes, and a healthcare professional should be consulted to assess individual circumstances.
Yes, weight loss is possible with low testosterone, though it may be more challenging. Addressing underlying hormonal imbalances alongside appropriate lifestyle changes is likely to be more effective than focusing on a single reason.
Where testosterone deficiency is clinically confirmed, testosterone treatment may also support improvements in body composition.
Yes. Testosterone helps regulate fat storage and distribution, particularly in the abdominal area. When levels fall, fat can accumulate more readily around the belly.
Yes. Treatment options for low testosterone depend on the underlying cause, symptoms and an individual’s overall health.
Testosterone replacement therapy (TRT) is a prescription treatment that may be considered for some men with clinically diagnosed testosterone deficiency. Research suggests that TRT may be associated with changes in body composition, including reductions in fat mass and increases in lean body mass in some men.
One long-term study of men with hypogonadism (a condition in which the body does not produce enough testosterone) reported significant reductions in body weight and waist circumference during TRT. However, individual responses vary, and results cannot be guaranteed.
A healthy lifestyle, which features maintaining a healthy weight, exercising regularly, managing stress and prioritising sleep, may also support overall hormonal health. Anyone concerned about low testosterone should seek advice from a qualified healthcare professional.
Weight changes during TRT treatment vary among individuals. Some men experience temporary fluid retention after starting testosterone therapy, which can lead to a short-term increase in weight. Others may notice changes in body composition over time. Increased appetite has also been reported by some men during treatment.
If you experience unexpected weight changes while receiving TRT, speak to your healthcare provider, who can assess whether further evaluation or treatment adjustments are needed.
Join the Envigore Men’s Forum for a safe space to discuss testosterone and weight gain and other symptoms and factors that can influence body weight and well-being.
Disclaimer: The information on this page is intended for general educational purposes only. This should not be considered a substitute for personalised medical advice. If you are concerned about weight gain and low testosterone, please consult your GP.
Sources & Further Reading
Hackett G, Kirby M, Rees RW, Jones TH, Muneer A, Livingston M, Ossei-Gerning N, David J, Foster J, Kalra PA, Ramachandran S. The British Society for Sexual Medicine Guidelines on Male Adult Testosterone Deficiency, with Statements for Practice. World J Mens Health. 2023 Jul;41(3):508-537. doi: 10.5534/wjmh.221027. Epub 2023 Feb 22. PMID: 36876744; PMCID: PMC10307648.
Saad, F., Yassin, A., Doros, G. et al. Effects of long-term treatment with testosterone on weight and waist size in 411 hypogonadal men with obesity classes I-III: observational data from two registry studies. Int J Obes 40, 162–170 (2016). https://doi.org/10.1038/ijo.2015.139
Fui MNT; Dupuis P; Grossmann M. Lowered testosterone in male obesity: mechanisms, morbidity and management. Asian Journal of Andrology 16(2):p 223-231, Mar–Apr 2014. | DOI: 10.4103/1008-682X.122365
Bhasin, S., et al. (2010). Testosterone therapy in men with androgen deficiency syndromes: an Endocrine Society clinical practice guideline. Journal of Clinical Endocrinology & Metabolism, 95(6), 2536–2559. https://doi.org/10.1210/jc.2009-2354
O’Neill, S., & O’Driscoll, L. (2015). Metabolic syndrome: a closer look at the growing epidemic and its associated pathologies. Obesity Reviews, 16(1), 1–12.
Rochira, V., et al. (2023). The complications of male hypogonadism: is it just a matter of low testosterone? Frontiers in Endocrinology, 14. https://doi.org/10.3389/fendo.2023.1201313
Leproult, R., & Van Cauter, E. (2011). Effect of 1 week of sleep restriction on testosterone levels in young healthy men. JAMA, 305(21), 2173–2174. https://doi.org/10.1001/jama.2011.710
About Your Clinical Team
This content was medically reviewed and approved by Danny Gian Hou Chu, a HCPC-Registered Physician Associate (PA38670), who oversees all prescribing decisions at Envigore.
All prescriptions are dispensed by Right Medicine Pharmacy, a GPhC-Registered Pharmacy (No. 9012382).
Nutritional guidance and lifestyle support are provided by Veronica Giudice, a HCPC-Registered Dietitian (DT26570) and British Dietetic Association member.
Last medically reviewed: June 2026