Eating for Better Sleep & Foods that Improve Metabolic Health | Dr. Marie-Pierre St-Onge

What It Covers

Dr. Marie-Pierre St-Onge, professor of nutritional medicine at Columbia University, presents research on the bidirectional relationship between sleep and food. Studies show sleep deprivation increases caloric intake by 250–400 calories daily, while dietary choices directly alter sleep architecture. Specific nutrients — fiber, saturated fat, refined carbohydrates — measurably change deep sleep duration and sleep quality.

Key Questions Answered

• •Sleep deprivation and hunger hormones differ by sex: Men restricted to four hours of sleep show elevated ghrelin, driving appetite upward. Women show reduced GLP-1, the satiety hormone, meaning the brake on eating is removed rather than the accelerator pressed. Both responses result in consuming roughly 300 extra calories per day in controlled lab settings — a mechanism worth recognizing before reaching for food after a poor night.
• •Mild, sustained sleep restriction causes measurable metabolic damage: Six weeks of sleeping six hours nightly — just 90 minutes less than a typical seven-and-a-half-hour baseline — increases insulin resistance, reduces insulin sensitivity, and raises blood pressure in free-living conditions. The effect is more pronounced in postmenopausal women. A single night of severe restriction in a controlled lab shows no glucose or cortisol changes, meaning the damage accumulates through compounding dietary and behavioral shifts over time.
• •Dietary fiber increases deep sleep; saturated fat and refined carbohydrates reduce it: Participants who self-selected meals containing more fiber spent significantly more time in slow-wave sleep. Higher saturated fat intake correlated with less deep sleep, while refined carbohydrates and simple sugars caused more arousals — transitions from deep to lighter sleep stages — without full waking. The self-selected diet also increased time to fall asleep by over 70% compared to a controlled, researcher-assigned meal plan.
• •Eating window timing shifts fat oxidation: Consuming the same foods, same calories, same meal spacing — but starting meals five hours after waking versus one hour after waking — reduces fat oxidation during the later eating window. Research by Martha Garaulet in Spain confirms that eating the largest meal earlier in the day produces better weight loss outcomes. Shifting roughly two-thirds of daily caloric intake to the first two-thirds of waking hours supports metabolic health and sleep quality.
• •MCT oil produces modest but real increases in caloric burn and body composition improvement: Purified medium-chain triglycerides — eight and ten carbon fatty acids — are metabolized directly in the liver rather than stored in adipose tissue. Consuming MCT oil in place of standard fat increases the thermic effect of food by approximately 45–60 calories per meal. Over four weeks, substituting MCT oil for olive oil in a controlled weight-loss study produced greater fat loss. One to two tablespoons daily as a replacement fat, not an addition, is the studied dose.
• •Mediterranean and DASH dietary patterns reduce insomnia risk over time: Analysis of the Women's Health Initiative cohort shows women whose diets align with Mediterranean or DASH patterns are less likely to develop persistent insomnia over a three-year follow-up. The DASH diet — emphasizing fruits, vegetables, nuts, seeds, low-fat dairy, and legumes — was originally designed to reduce hypertension and performs comparably to statin medication for cholesterol reduction when followed as the Portfolio Diet formulation including soy protein, nuts, plant sterols, and soluble fiber.
• •Finishing meals at least three hours before bedtime supports sleep quality and metabolic health: Eating close to bedtime raises core body temperature through the thermic effect of food, interfering with the natural cooling process required for sleep onset. Population data and controlled studies consistently show earlier eating windows improve cardiometabolic markers. Ginger dissolved in warm water consumed with meals increases the thermic effect of food through capsaicin receptor activation, potentially adding a small additive boost to energy expenditure when combined with earlier meal timing and MCT substitution.