DASH4D diet for glycemic control and glucose variability in type 2 diabetes: a randomized crossover trial

The Dietary Approaches to Stop Hypertension (DASH) diet is rich in foods (fruits, vegetables, whole grains) that may reduce hyperglycemia and glycemic variability. In this randomized crossover feeding trial, 89 participants with type 2 diabetes were fed four isocaloric diets in a random order: the DASH4D diet (a DASH-style diet tailored for diabetes) or a comparison (typical American) diet, each with higher (3,700 mg day^-1 at 2,000 kcal) or lower (1,500 mg day^-1 at 2,000 kcal) sodium. Each feeding period lasted 5 weeks. The primary outcomes were mean glucose; percentage of time spent with glucose between 70 and 180 mg dl^-1 (time in range); and coefficient of variation assessed using 14 days of continuous glucose monitoring during each feeding period. The DASH4D (versus comparison) diet significantly reduced mean glucose (mean difference = -11.1 mg dl^-1; P < 0.001), increased time in range (mean difference = +5.2 percentage points; P < 0.001) and had no effect on the coefficient of variation (P = 0.52). In analyses of secondary outcomes, glucose standard deviation and time spent with hyperglycemia (glucose >180 mg dl^-1 and >250 mg dl^-1) were lower in the DASH4D diet, but time spent with hypoglycemia (glucose <70 mg dl^-1 and <54 mg dl^-1) was similar across diets. There were no serious adverse events related to continuous glucose monitoring or the study diets. These results suggest that the DASH4D diet is a promising nutritional approach to substantially improve glycemic control in adults with type 2 diabetes. ClinicalTrials.gov registration: NCT04286555 .