Cortisol is produced by the adrenal glands in response to perceived threats, whether physical or psychological. Its acute release serves vital survival functions. Its chronic elevation, a consequence of sustained psychological stress, sleep deprivation, overtraining, or inflammatory conditions, produces a hormonal environment that is hostile to the body composition goals of most adults over 35.
Cortisol and Visceral Fat Deposition
Visceral adipocytes, the fat cells surrounding abdominal organs, express the highest density of glucocorticoid receptors in the body. Cortisol stimulates these receptors to promote fat storage and inhibit lipolysis in the visceral region specifically. This is why adults under chronic stress, or taking corticosteroid medication, preferentially accumulate abdominal fat even when total body weight is relatively stable.
Cortisol and Appetite
Chronic cortisol elevation increases appetite, particularly for calorie-dense, high-fat and high-sugar foods. This is mediated through the hypothalamus, where cortisol interferes with leptin signalling and increases the reward value of food in the nucleus accumbens. Stress eating is not a character weakness. It is a cortisol-mediated neurobiological response.
The Cortisol Reduction Protocol
- Sleep: the most powerful cortisol regulator available. Cortisol rises inversely with sleep quality.
- Moderate aerobic exercise: reduces next-day cortisol and improves HPA axis regulation
- Mindfulness practice: eight weeks of mindfulness-based stress reduction reduces morning cortisol by 15 to 20 percent
- Phosphatidylserine: one of the few supplements with consistent evidence for blunting the cortisol response to exercise
- Social connection: strong social support networks significantly reduce cortisol responses to identical stressors