The time of day certain types of foods are eaten may affect risks for cardiovascular disease and all-cause mortality for adults with diabetes, according to study data published in The Journal of Clinical Endocrinology & Metabolism.

“We observed that eating potatoes in the morning, whole grains in the afternoon, greens and milk in the evening and less processed meat in the evening was associated with better long-term survival in people with diabetes,” Qingrao Song, MD, of the department of nutrition and food hygiene at the Harbin Medical University School of Public Health in China, said in a press release. “Nutritional guidelines and intervention strategies for diabetes should integrate the optimal consumption times for foods in the future.”

Researchers analyzed data from 4,642 adults aged 18 years and older with diabetes who participated in the National Health and Nutrition Examination Survey from 2003 to 2014. Food intake data were collected during two nonconsecutive 24-hour dietary recalls, one taking place in person and the second occurring 3 to 10 days later by phone. Food consumption was analyzed in three time periods: morning, which consisted of breakfast plus a snack between breakfast and lunch; afternoon, including food eaten during lunch and a snack between lunch and dinner; and evening, including dinner plus any snack eaten after dinner. The cohort was divided into quantiles based on each participant’s intake of each food group. CVD and all-cause mortality data were obtained from the National Death Index through 2015. Researchers also built isocaloric models to analyze the RR of mortality when food intake was changed from one time period to another.

In the morning period, participants had a lower risk for CVD mortality if they were in the highest quantile for potatoes (HR = 0.46; 95% CI, 0.24-0.89), starchy vegetables (HR = 0.32; 95% CI, 0.15-0.72) and tomatoes (HR = 0.56; 95% CI, 0.33-0.97) compared with those in the lowest quantile for each of those groups. Adults in the highest quantiles for eating potatoes (HR = 0.71; 95% CI, 0.51-0.97), starchy vegetables (HR = 0.69; 95% CI, 0.49-0.95) and tomatoes (HR = 0.71; 95% CI, 0.53-0.94) during morning also had a decreased all-cause mortality risk compared with those in the lowest quantile.

In the afternoon, adults who consumed whole grains had a lower risk for CVD mortality compared with those who did not eat whole grains (HR = 0.67; 95% CI, 0.48-0.95). During the evening, people in the highest quantile for eating processed meat had a higher risk for CVD mortality compared with those in the lowest quantile (HR = 1.74; 95% CI, 1.07-2.82). Adults in the highest quantile for eating dark vegetables had a lower risk for CVD mortality compared with those in the lowest quantile (HR = 0.55; 95% CI, 0.35-0.87), and people in the highest quantile for drinking milk had a lower risk for CVD mortality (HR = 0.56; 95% CI, 0.36-0.88) and all-cause mortality (HR = 0.71; 95% CI, 0.54-0.92) compared with those in the lowest quantile.

In analysis of the isocaloric models, moving one-tenth of a serving of potatoes from afternoon or evening to morning decreased CVD mortality by 9%. Shifting one-tenth of a serving of starchy vegetables from afternoon to morning reduced CVD mortality by 14% and moving one-tenth of a serving from evening to morning lowered CVD mortality by 15%. CVD mortality declined 8% when one-tenth of a serving of dark vegetables was shifted from afternoon to evening. CVD mortality was reduced by 7% and all-cause mortality declined 3% when one-tenth of a serving of whole grain was moved from morning to the afternoon.

“The findings in our study have important implications,” the researchers wrote. “People with diabetes are under a disrupted biological rhythm of glucose metabolism, and accumulating evidence in recent years has indicated that food intake time is as important as quantity and quality for maintaining health. Therefore, nutritional therapy that considers consumption time will be a major component of diabetes treatment.”