You know the feeling: you're exhausted, but your brain won't shut off. You've tried the sleep masks, the white noise, the lavender spray. But what about your dinner plate? It turns out that what you eat—especially in the hours before bed—can quietly sabotage your rest and keep your stress hormones humming.
We spoke with dietitians to identify five common foods and drinks that can interfere with sleep quality and elevate cortisol, your body's primary stress hormone. The goal isn't to create a list of "forbidden" items, but to help you understand how your evening choices affect your nighttime biology.
1. Caffeinated Drinks and Late-Day Coffee
This one might seem obvious, but the timing matters more than many people realize. Caffeine has a half-life of roughly five to six hours. That means if you have a large iced coffee at 3 p.m., half of that caffeine is still circulating in your bloodstream at 8 or 9 p.m. "Caffeine blocks adenosine, the chemical that makes you feel sleepy," explains registered dietitian Sarah Thompson, RD. "Even a small amount late in the day can fragment your sleep and trigger a mild cortisol spike."
Dietitians recommend cutting off all caffeinated beverages—including coffee, black tea, green tea, and many sodas—by early afternoon. If you crave a warm evening drink, opt for a naturally caffeine-free herbal tea like chamomile or rooibos.
2. Spicy Foods
A bowl of chili or spicy curry might feel comforting, but it can be a recipe for restless sleep. Capsaicin, the compound that gives chili peppers their heat, raises your core body temperature. "Your body needs to cool down slightly to initiate and maintain deep sleep," says Dr. Maya Chen, a clinical dietitian. "Spicy foods can interfere with that thermoregulation process."
Additionally, spicy meals can trigger acid reflux or heartburn in some people, which becomes worse when lying down. The combination of physical discomfort and a slightly elevated core temperature can raise cortisol levels and make it harder to fall—and stay—asleep. If you love heat, enjoy spicy dishes at lunch rather than dinner.
3. High-Sugar Desserts and Refined Carbs
That slice of cake or bowl of ice cream before bed may be doing more than adding calories. High-sugar foods cause a rapid spike in blood glucose, which prompts your body to release insulin. Shortly after, blood sugar can crash. "These swings in blood glucose can trigger the release of adrenaline and cortisol as a regulatory response," explains dietitian nutritionist Rachel Greene, RDN. "That hormonal surge can wake you up in the middle of the night or make your sleep less restorative."
Refined carbohydrates—white bread, pasta, crackers, and sugary cereals—have a similar effect. For a bedtime snack, choose something that pairs protein or healthy fat with a small amount of complex carbohydrates. Think a tablespoon of almond butter on a whole-grain cracker or a small bowl of plain Greek yogurt with berries.
4. Alcohol
Alcohol is a double-edged sword for sleep. While a glass of wine might help you fall asleep faster, it severely disrupts the second half of the night. "Alcohol suppresses REM sleep, which is the restorative stage where memory consolidation and emotional processing occur," says Dr. Chen. "It also acts as a diuretic, meaning you're more likely to wake up to use the bathroom."
Moreover, as your body metabolizes alcohol throughout the night, it can cause a rebound effect of lighter, more fragmented sleep—often accompanied by a small cortisol spike. The result: you wake up feeling less rested, even if you slept for eight hours. Dietitians generally advise stopping alcohol consumption at least three hours before bedtime.
5. Fatty or Heavy Meals Close to Bedtime
A large, high-fat meal—think a greasy burger, a plate of fried chicken, or a creamy pasta—takes longer to digest. Lying down shortly after eating can cause discomfort, bloating, and acid reflux, all of which can make it difficult to fall asleep. "Your digestive system is active when it should be winding down," says Thompson. "That metabolic activity can raise your heart rate and core body temperature, both of which signal to your body that it's not yet time for deep rest."
To avoid this, try to finish your last substantial meal at least two to three hours before you plan to go to bed. If you need a small snack later, keep it light—a small banana, a handful of nuts, or a glass of warm milk.
Understanding how your eating patterns affect your sleep and stress hormones is a powerful step toward better health. Instead of rigid rules, think of it as gentle awareness. By making small shifts—like choosing a different afternoon drink, swapping a late-night dessert for a balanced snack, or eating your last heavy meal earlier—you can create the conditions for deeper, more restorative sleep and a calmer stress response.
