Effects of the Dietary Approaches to Stop Hypertension Diet Alone and in Combination With Exercise and Caloric Restriction on Insulin Sensitivity and Lipids

This study examined the effects of the Dietary Approaches to Stop Hypertension (DASH) diet on insulin sensitivity and lipids. In a randomized control trial, 144 overweight (body mass index 25–40) men (N= 47) and women (N= 97) with high blood pressure (130–159/85–99 mm Hg) were randomly assigned to either: (1) DASH diet alone (DASH-A); (2) DASH diet with aerobic exercise and caloric restriction (DASH-WM); or usual diet controls (UC). Body composition, fitness, insulin sensitivity, and fasting lipids were measured before and following 4 months of treatment. Insulin sensitivity was estimated based on glucose and insulin levels in the fasting state and after an oral glucose load. Participants in the DASH-WM condition lost weight (−8.7 [95% CI = −2.0, −9.7] kg,), and exhibited a significant increase in aerobic capacity, while the DASH-A and UC participants maintained their weight (−0.3 [95% CI = −1.2, 0.5] kg and +0.9 [95% CI = 0.0, 1.7] kg, respectively) and had no improvement in exercise capacity. DASH-WM demonstrated lower glucose levels following the oral glucose load, improved insulin sensitivity, and lower total cholesterol and triglycerides compared to both DASH-A and UC, and lower fasting glucose and low-density lipoprotein cholesterol compared to UC; DASH-A participants generally did not differ from UC in these measures. Combining the DASH diet with exercise and weight loss resulted in significant improvements in insulin sensitivity and lipids. Despite clinically significant reductions in blood pressure, the DASH diet alone, without caloric restriction or exercise, resulted in minimal improvements in insulin sensitivity or lipids