Five Daily Cups of Produce May Improve Sleep in Just One Night

Swapping convenience food for an extra serving of salad may pay off before your head even hits the pillow. Adults who increased their fruit-and-vegetable consumption to about five cups a day experienced a 16 percent jump in sleep quality the very next night, according to a Columbia University study published this week in Sleep Health.

The experiment tracked 34 healthy volunteers, ages 20 to 49, through two six-week phases. Participants logged everything they ate and wore actigraphy wristbands to measure how often they awoke after falling asleep—a marker known as sleep fragmentation. Higher daytime intakes of produce, complex carbohydrates and fiber were linked to less fragmented sleep, while greater consumption of red or processed meat predicted poorer rest.

Key findings  

• Zero to five cups of fruits and vegetables: 16 % improvement in sleep quality.  

• More carbohydrates and fiber: additional gains in restorative sleep.  

• Added sugars showed no connection to sleep, suggesting the benefits come from produce-based carbs and fiber rather than sweets.  

• Processed meat intake correlated with less efficient sleep.

“It’s good to know there are foods that actively promote better sleep, not just habits to avoid,” said lead author Marie-Pierre St-Onge, PhD, director of Columbia’s Center of Excellence for Sleep and Circadian Research.

Why produce helps  

Carbohydrate-rich fruits and vegetables may increase the brain’s uptake of tryptophan, an amino acid converted to the sleep-regulating hormone melatonin. Dietitians also point to the fiber, vitamins and antioxidants in plant foods, which support gut-brain signaling and hormone balance.

Earlier work has tied Mediterranean-style diets to lower rates of insomnia and showed that fiber-rich menus deepen slow-wave sleep. The new research strengthens the case by demonstrating next-day effects rather than long-term associations, said Erica Jansen, PhD, a nutritional epidemiologist at the University of Michigan who was not involved in the study.

Practical tweaks  

Experts advise adding, not subtracting: throw spinach into pasta, keep a plate of raw vegetables on the dinner table, or pair snacks with produce. Frozen, canned or pre-cut options count toward the five-cup target and require little prep time.

“Include a fruit or veggie at every meal or snack,” said registered dietitian Sheri Gaw of El Camino Hospital. “Most people find their cravings for less-nutritious foods decline naturally.”

The researchers acknowledge that diet and sleep influence each other—sleep-deprived people often reach for sugary, high-fat foods. Still, after adjusting for exercise, calorie intake and other lifestyle factors, the produce-sleep link held firm.

“The message is straightforward,” St-Onge said. “If you want a better night’s rest, start by filling half your plate with fruits and vegetables.”