The hormone–metabolism connection
Many men struggle with weight gain despite eating well and exercising. Testosterone deficiency may contribute to this problem by slowing metabolism. Research shows that testosterone deficiency is associated with metabolic disorders such as metabolic syndrome and type 2 diabetes. Low testosterone increases lipoprotein lipase activity, leading to increased fatty acid uptake, triglyceride formation and visceral fat accumulation. These changes slow your metabolism and make weight gain feel inevitable.
A cycle of obesity and low testosterone
The relationship between testosterone and metabolic health is bidirectional. Visceral fat increases aromatase activity, converting testosterone to estrogen and further lowering testosterone. Inflammatory cytokines such as TNF‑α, IL‑6 and IL‑1β, which are elevated in obesity, suppress hormone signaling and reduce testosterone production. Insulin resistance and leptin also inhibit hormone secretion. This vicious cycle makes it hard to lose weight and can lead to fatigue and insulin resistance.
Story: Peter’s progress
Peter, 55, struggled to lose weight despite a low‑calorie diet. His waistline expanded, and his energy plummeted. Tests revealed low free testosterone and signs of metabolic syndrome. By improving his nutrition, incorporating strength training and using hormone therapy under supervision, Peter broke the cycle. His visceral fat decreased, and his metabolism improved.
Conventional vs functional solutions
Conventional care often recommends calorie restriction and aerobic exercise for weight loss. Hormone testing may not be considered until weight issues become severe. Functional medicine evaluates testosterone, insulin resistance, inflammatory markers and other hormones to understand why metabolism has slowed. Treatment may include resistance training, nutrient optimization, stress reduction and targeted hormone therapy through testosterone replacement therapy programs when appropriate.
Final thoughts
If you feel like you’re gaining weight no matter what you do, consider having your hormones checked. Addressing testosterone deficiency and metabolic imbalances can make weight loss possible.
