The Impact of Diet on Sleep

Approximately one-third of adults experience insufficient sleep, making research into the relationship between nutrition and sleep crucial for improving sleep problems. This document discusses which foods may aid sleep, which could negatively impact sleep quality, and answers common questions on the topic.

The Relationship Between Nutrition and Sleep

On one hand, studies have found that foods containing the amino acid tryptophan can improve sleep quality. However, research on nutrition and sleep concludes that due to the design of most studies on this topic, there is insufficient evidence to confirm that specific foods or dietary patterns directly affect sleep. Instead, the authors suggest that obesity—not specific foods—may be the primary factor influencing sleep.

While more research is needed to fully understand how foods impact sleep, studies show that sleep patterns influence eating behaviors and the body’s response to food. Sleep deprivation (less than 7 hours of sleep per night for adults) may increase feelings of hunger, make high-sugar and high-fat foods more appealing, and lead to overeating. It can also reduce the body’s ability to break down sugar, increasing the risk of obesity, type 2 diabetes, and heart disease.

Foods That May Aid Sleep

Research suggests the following foods may promote better sleep:

• Sour cherry juice
• Cherries
• Kiwi
• Fatty fish (e.g., herring, mackerel, salmon, tuna, sardines, trout, krill)
• Oysters
• Poultry
• Milk and cheese
• Eggs
• Bread
• Beans
• Pumpkin seeds
• Vegetable-rich diets
• Cereal mixes containing tryptophan

Studies also found that consuming simple carbohydrates (which quickly convert to sugar in the bloodstream) 4 hours before bed may help people fall asleep faster. However, relying on simple carbs before bed is not a long-term solution for improving sleep, as high-sugar and high-carb diets are associated with poorer sleep quality. A balanced diet with moderate intake of carbohydrates, protein, and fat appears most conducive to good sleep.

Foods That May Impact Sleep Negatively

Certain foods, beverages, and eating habits may reduce sleep duration or quality:

• Caffeinated foods and drinks
• Alcoholic foods and drinks
• High-fat foods (especially saturated fats)
• High-sugar foods
• Foods low in tryptophan
• Diets low in dietary fiber
• High-carbohydrate, low-fat diets

Irregular meal times, snacking between meals or after dinner, and overeating—especially close to bedtime—can also disrupt sleep.

How to Improve Sleep Quality Through Diet

Try these research-backed tips to enhance sleep via diet and nutrition:

1. Maintain a Balanced Diet:
   Include moderate amounts of the three macronutrients (carbohydrates, fat, protein). Whole grains are preferable to simple carbs or highly processed grains, as they are healthier and may aid sleep. Excessive or insufficient protein intake has been shown to negatively impact sleep.
2. Eat Fruits and Vegetables:
   A balanced diet should include adequate fruits and vegetables. Consuming fiber- and vitamin-rich produce is linked to better sleep.
3. Stick to a Regular Eating Schedule:
   Meal timing affects circadian rhythms, which in turn influence sleep-wake cycles. Late-night eating or eating within two hours of bedtime may reduce sleep quality. Irregular meal times are also associated with poorer sleep and higher obesity rates.
4. Avoid Sleep Disruptors:
   • Caffeine: Disrupts sleep even when consumed 6 hours before bed (found in tea, coffee, soda, energy drinks, and chocolate).
   • Alcohol: While it may help some fall asleep faster, it ultimately reduces sleep quality and causes nighttime awakenings.
5. Prevent Nocturnal Acid Reflux:
   Acid reflux can disturb sleep. Foods like spicy dishes, fried foods, high-fat meals, and junk food increase the risk of reflux. Avoid these foods and stop eating 2 hours before bed to minimize nighttime discomfort and sleep disruption.

Common Questions About Diet and Sleep

Does the Body Digest Food During Sleep?

Metabolism slows during sleep, which is why most people defecate while awake and why acid reflux is more common at night.

Does Metabolism Slow Down During Sleep?

A person’s basal metabolic rate (the energy burned by the brain and body) decreases overall during sleep but rises during rapid eye movement (REM) sleep—the stage associated with vivid dreams, which increases in the second half of the night.

Can Sleep Help You Lose Weight?

Some studies link good sleep hygiene to weight loss and fat reduction, while sleep deprivation may lead to weight gain. Insufficient sleep disrupts hormones, increasing obesity risk by boosting hunger, encouraging unhealthy food choices, and reducing physical activity.

Can Unhealthy Diets Cause Sleep Disorders?

While diet has not been proven to directly cause sleep disorders, certain eating habits may be linked to or worsen them. For example, poor nutrition can contribute to insomnia, and unhealthy diets may lead to obesity, which increases the risk of obstructive sleep apnea (OSA). Irregular meal times can also disrupt circadian rhythms, exacerbating symptoms of circadian rhythm sleep disorders.