Influence of the DASH Diet on Gestational Weight Gain and Perinatal Outcomes in Women with Pre-Existing Diabetes Mellitus: A Randomized, Single-Blind, Controlled Clinical Trial.

Abstract

This study aimed to investigate the influence of the dietary approaches to stop hypertension (DASH) diet on gestational weight gain and perinatal outcomes in pregnant women with pre-existing diabetes mellitus (PDM). A randomized, single-blind, controlled clinical trial was conducted with 68 pregnant women with PDM throughout prenatal care until delivery (18 weeks) at a public maternity hospital in Rio de Janeiro, Brazil (2016-2020). The standard diet adopted by the control group (standard diet group-SDG) contained 45-55% carbohydrates, 15-20% protein, and 25-30% lipids of the total energy intake. An adapted DASH diet, with a similar macronutrient composition, but with higher calcium, potassium, magnesium, fiber, and reduced saturated fat, was prescribed for the intervention group (DASH diet group-DDG). Student's t- or Mann-Whitney U tests were used to compare outcomes between groups. To assess the trajectory of gestational weight gain throughout the intervention between the study groups, linear mixed-effects regression models were used. The DDG had lower gestational weight gain at the fifth (p = 0.03) and seventh appointment (p = 0.04), with no difference in average total gestational weight gain (SDG: 10 kg [SD = 4]; DDG: 9 kg [SD = 5], p = 0.23). There was a trend for a lower length of stay of the newborns (p = 0.08) in the DDG without differences for other perinatal outcomes. The DASH diet promoted less variation in gestational weight gain without promoting a difference in total gestational weight gain, and there was no difference between the study groups for perinatal outcomes.