Effect of nutrition education on weight gain and macronutrients intake during pregnancy: a randomized clinical trial

Background and aims: The imbalance between energy intake and consumption has been recognized as an important factor contributing to the gestational weight gain (GWG). Additionally, the determination of the effect of macronutrient composition on GWG has been recommended by researchers. Therefore, we examined the effect of nutrition education on weight gain, energy, and energy-adjusted macronutrients intake during three trimesters of pregnancy which have not been widely studied. Methods: This randomized single-blinded clinical trial was performed on 192 primiparous pregnant women in Isfahan, Iran, from May 2015 to September 2016. Data were collected using a questionnaire completed through interviews with pregnant women and prenatal care-related records. We developed an individualized calorie-appropriate diet for each participant at enrollment and then three 45-60 minute training sessions were held at 6-10, 18, and 26 weeks of pregnancy and the subjects’ weights were measured during these sessions. A consecutive 3-day food intake record at 6-10, 18 and 34-36 weeks was obtained from two groups to determine the macronutrients. Moreover, physical activity scores were estimated before and after the intervention. Results: The mean weights at 18, 26, and 40 weeks of gestation were significantly lower in the intervention group ( P = 0.024, P = 0.040, and P = 0.015, respectively). The total energy, energy-adjusted carbohydrate and protein intake at 6-10, 18, and 34-36 weeks of gestation were not significantly different between the two groups (P 0.05). However, the mean energy-adjusted fat intake decreased ( P = 0.043). In addition, the mean energy-adjusted dietary fiber intake was significantly higher in the intervention group ( P = 0.001). Conclusion: In the present individualized calorie-appropriate trial, the mean weights decreased during three trimesters in the intervention group. Additionally, calorie, energy-adjusted carbohydrate and protein intake did not change after intervention while energy-adjusted fat intake decreased.