The impact of caloric restriction on testosterone is context-dependent. While it can improve testosterone levels in men with obesity or metabolic syndrome, the same dietary stress will likely decrease testosterone in young, healthy, lean men.
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Cannabinoids (THC, CBD) don't directly reduce testosterone. Instead, the act of smoking marijuana increases the enzyme aromatase, which converts testosterone into estrogen. Higher estrogen then signals the pituitary to reduce testosterone production, creating an indirect negative feedback loop.
Contrary to popular belief, fasting for up to four days actually increases your basal metabolic rate. Instead of shutting down to conserve energy, your body activates a hormonal 'fight-or-flight' response that increases energy expenditure to help you find food.
Reducing calorie intake triggers a corresponding drop in your basal metabolic rate. Your body simply starts burning fewer calories to match what you're eating, which stalls weight loss and explains why "just eat less" is flawed advice.
Patients can successfully request hormone tests by describing subjective declines in energy, focus, or athletic performance compared to their past selves. This provides the necessary clinical justification for the lab work without requiring a pre-existing diagnosis.
Unlike simple calorie restriction, intermittent fasting lowers insulin levels. This hormonal signal allows your body to access and burn its fat stores to make up for a caloric deficit, preventing the metabolic slowdown that typically sabotages diets.
Instead of chasing weight loss, focus on foundational health markers like inflammation, blood sugar balance, stress levels, and nutrient deficiencies. When these systems are optimized, sustainable weight loss and body recomposition often occur as a natural side effect.
When addressing hormone imbalances, start at the base of the "hormone pyramid." Optimizing foundational hormones like cortisol (stress) and insulin (blood sugar) is essential, as they directly impact thyroid function and sex hormones like estrogen and testosterone.
Eating high-carb foods frequently, even in a calorie deficit, keeps insulin high. This prevents your body from accessing stored fat for energy, forcing it to lower its metabolic rate. After the diet, this suppressed metabolism causes rapid weight regain.
Research on "The Biggest Loser" contestants revealed that metabolic slowdown is a response to significant calorie restriction and exercise. Counterintuitively, those with the largest metabolic slowdown were the most successful at losing weight and keeping it off.
A major pitfall of intermittent fasting is the loss of lean muscle tissue. To counteract this, it must be combined with dedicated resistance training. This combination allows for the metabolic benefits of fasting while signaling the body to retain and even build muscle, which can be tracked through strength gains.
