Stopping food intake at least three hours before bedtime may improve heart health, according to a new study published in Arteriosclerosis, Thrombosis and Vascular Biology. Researchers found that extending the overnight prompt—to between 13 and 16 hours—compared to a habitual fasting period of 11 to 13 hours, led to lower nighttime blood pressure and heart rate in overweight and obese adults.
The study, involving 39 participants aged 36 to 75, also revealed that the extended fast group experienced improved blood sugar management and insulin sensitivity after consuming a glucose test. Participants in both groups were also asked to dim the lights three hours before bed.
“Lowering blood pressure and heart rate during sleep is called nocturnal dipping and is considered to be a healthy pattern,” explained Dr. Phyllis Zee, study co-author and director of the Center for Circadian and Sleep Medicine at Northwestern University’s Feinberg School of Medicine. “Lack of dipping is a risk for cardiovascular disease.”
The findings suggest a potential benefit to “time-restricted eating” aligned with the body’s natural circadian rhythm. Researchers described the approach as a “novel, accessible lifestyle intervention with promising potential for improving cardiometabolic function.” The improvements in blood pressure, heart rate, and blood sugar were observed without participants reducing their overall calorie intake.
Experts note that eating close to bedtime can interfere with sleep. “The body is primed for sleep, not to digest food at night,” said Sonya Angelone, a registered dietitian nutritionist based in San Francisco. The rise of the sleep hormone melatonin, which begins two to three hours before bed, also influences cardiovascular function, according to Dr. Zee.
Digestion itself can disrupt sleep, as blood pressure temporarily increases after a meal. Jessica Cording, a registered dietitian and author, explained that eating a large meal before bed can also raise blood sugar and potentially lead to feelings of alertness that interfere with sleep. Eating close to bedtime may increase the risk of acid reflux, further impacting sleep quality, Angelone added.
Poor sleep is linked to a range of health problems, including high blood sugar, high blood pressure, type 2 diabetes, and heart disease. Research suggests that eating too much before bed may also impact cortisol levels, potentially affecting body composition. The body also processes calories more efficiently earlier in the day, suggesting that shifting food intake earlier could support weight management efforts, Angelone said.
While the study’s results are promising, researchers caution that they may not be generalizable to the broader population. Angelone recommends gradually adjusting eating habits, suggesting a shift of 15 minutes earlier each day for those accustomed to a bedtime snack. Cording emphasized the importance of adequate nutrition throughout the day, noting that some individuals may be undereating during the day and overeating at night, which can contribute to metabolic issues.
Cording suggested that increasing food intake during the day and reducing it at dinner could be a “game-changer.” Angelone stressed the importance of a balanced dinner containing protein, healthy fats, and fiber to promote fullness and stabilize blood sugar.
Researchers acknowledge that adhering to a strict eating schedule every night may not always be feasible. “Give yourself some grace. It’s not necessarily about getting it perfect every day. It’s about long-term patterns over the lifespan,” Cording said.