Hormonal Timing

The most favorable window for visceral fat mobilization combines low insulin, remaining overnight growth hormone, rising cortisol, partial glycogen depletion, and available beta-adrenergic receptors. Growth hormone pulses during slow-wave sleep support tissue repair and stimulate hormone-sensitive lipase. The normal cortisol awakening response rises sharply after waking and helps mobilize stored energy. Morning cortisol is described as especially relevant to visceral fat because visceral fat has more glucocorticoid receptors than subcutaneous fat. By early morning after 11 to 12 hours without food, insulin is usually at its daily low and liver glycogen is partially depleted. Fasting can amplify overnight growth hormone pulses, while late eating can blunt the first important sleep-cycle pulse.