From counting sheep to trying white noise or using weighted blankets, people have explored countless ways to improve theirsleep. Poor sleep, however, continues to take a serious toll, influencing heart and metabolic health, memory, learning, productivity, emotional balance, and even relationships. Now, scientists say one surprisingly effective aid for better sleep might already be on your grocery list. Researchers from the University of Chicago Medicine and Columbia University discovered that eating more fruits and vegetables during the day was linked to more restful, higher-quality sleep later that night. "Dietary modifications could be a new, natural and cost-effective approach to achieve better sleep," said co-senior author Esra Tasali, MD, director of the UChicago Sleep Center. "The temporal associations and objectively-measured outcomes in this study represent crucial steps toward filling a gap in important public health knowledge." Previous studies have shown that getting too little sleep can drive people toward unhealthier eating patterns, often higher in fat and sugar. Yet, despite how sleep influences well-being and productivity, scientists have known far less about the reverse -- how diet affects sleep itself. While earlier research linked greater fruit and vegetable intake with people reporting better sleep, this study was the first to show a same-day relationship between diet and objectively measured sleep quality. For the research, healthy young adults logged their daily food intake using an app and wore a wrist monitor that tracked their sleep. The scientists analyzed a measure called "sleep fragmentation," which captures how often a person wakes up or shifts between lighter and deeper stages of sleep during the night. The results showed that daily eating habits were strongly connected to how well participants slept that night. Those who ate more fruits and vegetables -- and consumed more complex carbohydrates such as whole grains -- experienced longer periods of deep, undisturbed sleep. According to the team's analysis, people who met the CDC recommendation of five cups of fruits and vegetables per day could see an average 16 percent improvement in sleep quality compared with those who ate none. "16 percent is a highly significant difference," Tasali said. "It's remarkable that such a meaningful change could be observed within less than 24 hours." Future research will investigate whether the relationship is causal, explore the biological mechanisms involved, and test the results in broader and more diverse groups. Still, the researchers say current evidence strongly supports making fruits, vegetables, and whole grains a daily habit for better long-term sleep health. "People are always asking me if there are things they can eat that will help them sleep better," said co-senior author Marie-Pierre St-Onge, PhD, director of the Center of Excellence for Sleep & Circadian Research at Columbia. "Small changes can impact sleep. That is empowering -- better rest is within your control." Hedda L. Boege, Katherine D. Wilson, Jennifer M. Kilkus, Waveley Qiu, Bin Cheng, Kristen E. Wroblewski, Becky Tucker, Esra Tasali, Marie-Pierre St-Onge. Higher daytime intake of fruits and vegetables predicts less disrupted nighttime sleep in younger adults. Sleep Health, 2025; 11 (5): 590 DOI: 10.1016/j.sleh.2025.05.003