A recent study evaluated the impact of macronutrient distribution throughout the day on mortality risk in patients with diabetes.
There is no doubt that healthy dietary habits play an essential role in the management of diabetes. However, there is growing evidence that the timing and quantity of meals may also significantly affect glucose metabolism. Studies have reported that skipping breakfast or eating high amounts of energy at dinner can disrupt clock gene expression and lead to hyperglycemia. Yet, confusion remains on how to effectively distribute energy and macronutrient intake throughout the day to optimize glycemic control and improve survival among these patients.
A recent study sought to determine the effect of differences in macronutrient intake between dinner and breakfast on diabetes, CV, and all-cause mortality. This study included adult patients with diabetes (defined as an A1C 6.5%, FPG of approximately 127 mg/dL, or a self-reported diagnosis) who enrolled in the National Health and Nutrition Examination Survey between 2003 and 2014 in the United States. There was a total of 4699 participants, which included a similar number of men and women. Researchers assessed nutritional intake via a 24-hour dietary recall conducted for two non-consecutive days, which captured all meals and classified them as main meals or snacks. The study used 99% CI, HR, and Cox proportional hazards models to analyze how differences in total energy and macronutrients at different mealtimes would affect the primary outcome. They defined a statistically significant effect as a p <0.01 to avoid a false-positive result. The cause of death among participants was identified using the National Death Index (NDI) and ICD-10 codes, and survival was evaluated from the time of the interview to the end of 2015.
This study divided participants into quintiles of approximately equal numbers with the lowest quintile representing the group with the smallest change in macronutrient intake between dinner and breakfast (Δ= dinner – breakfast). Baseline characteristics were similar among the groups; however, patients with the highest energy consumption at dinner (quintile 5) were younger, men, non-Hispanic white, and had a higher BMI. After data analysis, they found that carbohydrate intake differences between dinner and breakfast did not significantly affect mortality in patients with diabetes. On the other hand, energy intake differences from fat and protein significantly affected outcomes in these patients. The HR showed that patients with the highest difference in total energy intake between dinner and breakfast (quintile 5) had a higher risk of diabetes (HR 1.92) and CV (HR 1.69) mortality. Patients consuming more fat (HR 1.67) or unsaturated fatty acids (HR 1.85) at dinner also had a higher risk of CV mortality. Differences in protein intake at dinner also significantly increased the risk of diabetes (HR 1.92), CV (HR 1.96), and all-cause (HR 1.46) mortality among patients with diabetes. Higher animal protein consumption at dinner compared to breakfast also showed an increased risk of diabetes (HR 1.94) and all-cause (HR 1.49) mortality.
This study used isocaloric models to replace 5% of a specific macronutrient from dinner with breakfast while keeping everything else constant. Substituting 5% of total energy at dinner with breakfast reduced the risk of diabetes mortality by 4% (HR 0.96) and the risk of CV mortality by 5% (HR 0.95). Additionally, replacing 5% of total fat or protein at dinner with 5% of total energy from carbohydrate, protein, or unsaturated fatty acids at breakfast showed the highest reduction in diabetes and CV mortality. Substituting 5% of fat from dinner with carbohydrates, protein, or unsaturated fatty acids at breakfast reduced the HR for diabetes mortality by 7%, 9%, and 10%, respectively, and the HR for CV mortality by 5%, 12%, and 11%, respectively. A similar association was seen when replacing 5% of total energy from protein at dinner with carbohydrate, protein, or unsaturated fatty acid at breakfast. However, sensitivity analyses showed varied results on the effect of replacing fat from dinner and mortality risk.
Of the 4699 participants included in the study, a total of 913 deaths were reported, which included 269 deaths due to diabetes and 314 deaths due to CVD. Given these results, more specific guidance on energy and macronutrient distribution throughout the day would be beneficial in patients with diabetes. These patients would benefit from a lower macronutrient intake at dinner compared to breakfast, considering the beneficial effects observed when replacing 5% of total energy at dinner with breakfast on mortality risk. Further studies are needed to evaluate the long-term effects of this method on mortality risk in patients with diabetes.
- Higher consumption of fat or protein at dinner compared to breakfast was associated with increased mortality in patients with diabetes.
- Replacing 5% of fat or protein at dinner with 5% from carbohydrate, protein, or unsaturated fatty acids at breakfast may reduce mortality.
- Patients should be educated on adequate energy and macronutrient distribution throughout the day and its beneficial effects.
Han, Tianshu, et al. “The Association of Energy and Macronutrient Intake at Dinner Versus Breakfast With Disease-Specific and All-Cause Mortality Among People With Diabetes: The U.S. National Health and Nutrition Examination Survey, 2003–2014” Diabetes Care, vol 43, issue 7, 2020, pp. 1442-1448. doi: 10.2337/dc19-2289.
Leyany Feijoo Ramos, PharmD. Candidate, LECOM School of Pharmacy