Comparing Very Low-Carbohydrate vs DASH Diets for Overweight or Obese Adults With Hypertension and Prediabetes or Type 2 Diabetes: A Randomized Trial

PURPOSE Adults with a triple multimorbidity (hypertension, prediabetes or type 2 diabetes, and overweight or obesity), are at increased risk of serious health complications, but experts disagree on which dietary patterns and support strategies should be recommended. METHODS We randomized 94 adults from southeast Michigan with this triple multimorbidity using a 2 × 2 diet-by-support factorial design, comparing a very low-carbohydrate (VLC) diet vs a Dietary Approaches to Stop Hypertension (DASH) diet, as well as comparing results with and without multicomponent extra support (mindful eating, positive emotion regulation, social support, and cooking). RESULTS Using intention-to-treat analyses, compared with the DASH diet, the VLC diet led to greater improvement in estimated mean systolic blood pressure (−9.77 mm Hg vs −5.18 mm Hg; P = .046), greater improvement in glycated hemoglobin (−0.35% vs −0.14%; P = .034), and greater improvement in weight (−19.14 lb vs −10.34 lb; P = .0003). The addition of extra support did not have a statistically significant effect on outcomes. CONCLUSIONS For adults with hypertension, prediabetes or type 2 diabetes, and overweight or obesity, the VLC diet resulted in greater improvements in systolic blood pressure, glycemic control, and weight over a 4-month period compared with the DASH diet. These findings suggest that larger trials with longer follow-up are warranted to determine whether the VLC diet might be more beneficial for disease management than the DASH diet for these high-risk adults.