Effect of dietary and lifestyle intervention in pregnant women: randomized clinical trial

To evaluate the intra- and between-group (control and intervention) effect of counseling during pregnancy on pregnant women's food consumption and physical activity.

This randomized, parallel, two-arm clinical trial was carried out in primary health care in a Brazilian municipality from 2018 to 2021. Adult pregnant women with pre-gestational overweight (n = 350) were randomly assigned to the control or intervention groups. The intervention consisted of three counseling sessions based on the NOVA food classification system and encouragement toward physical activity. Then, 24-hour dietary records were obtained, and physical activity was assessed using a structured questionnaire. The Wilcoxon test was used for intra-group differences between assessments and the Mann-Whitney test, for differences between groups.

Women in the control group consumed less minimally and unprocessed foods (%E) (Δ = -4.08; -13.58 to 4.34; p = 0.006) and more ultra-processed foods (%E) (Δ = 3.74; -5.86 to 12.86; p = 0.009), with no difference between groups. The intervention group showed an increase in commuting-related physical activity (min/week) between assessments (Δ = 9.00; -30.00 to 70.00; p = 0.02), with no difference between groups. The other parameters showed no differences.

The intervention failed to affect outcomes. However, intragroup changes showed that the control consumed less minimally and unprocessed foods and more ultra-processed foods and the intervention group increased their commuting-related physical activities.