Circadian Metabolism

Intermittent fasting is most effective when aligned with the body's biological timer. The same meal causes a stronger and longer insulin response in the evening than in the morning. The same meal causes a worse glucose response at night than in the morning. Ending food intake earlier is framed as biological alignment rather than deprivation. The article argues that calories-in versus calories-out is incomplete because it ignores circadian glucose handling. A carbohydrate meal at 7 AM may produce a larger insulin spike than the same meal at 11 AM. Evening diet-induced thermogenesis is described as lower than morning thermogenesis. Evening glucose processing can require substantially more insulin than morning glucose processing. Identical calorie intake may produce a higher thermogenic increase in the morning than in the evening. Cells become less sensitive to insulin as the day moves toward evening. Insulin sensitivity is described as following a circadian rhythm and being strongest in the morning. Clock genes regulate insulin sensitivity, fat oxidation, liver glucose processing, and nutrient storage versus burning. The body generally favors fuel utilization in late morning and ear…