Effect of a diet intervention during pregnancy on dietary behavior in the randomized controlled Norwegian Fit for Delivery study

A mother's diet during pregnancy has the potential to influence both her own and her child's short- and long-term health. This paper reports the effects of a randomized controlled diet intervention during pregnancy on dietary behavior post-intervention as reported in late pregnancy. The diet intervention was part of a lifestyle intervention targeting both diet and physical activity behaviors among nulliparous women participating in the randomized controlled Norwegian Fit for Delivery study (NFFD). Eligible women were enrolled in early pregnancy from eight healthcare clinics in southern Norway between 2009 and 2013. The diet intervention was based on 10 dietary recommendations that were conveyed during two counseling sessions by phone and in a pamphlet describing the recommendations and their simplified rationale. A diet score was constructed from a 43-item food frequency questionnaire (FFQ) and used to assess intervention effect on dietary behavior (score range 0-10). Between-group dietary differences post-intervention were estimated with analysis of covariance, with adjustment for baseline diet. A total of 508 women completed the FFQ both at baseline and post-intervention. There were no between-group differences in diet score and subscales at baseline. Post-intervention, the intervention group had higher overall diet score (control: 4.61, intervention: 5.04, P=0.013) and favorable dietary behavior in seven of the 10 dietary domains: 'consumption of water relative to total beverage consumption' (P=0.002), 'having vegetables with dinner' (P=0.027), 'choosing fruits and vegetables for between-meal snacks' (P=0.023), 'buying small portion sizes of unhealthy foods' (P=0.010), 'limiting sugar intake' (P=0.005), 'avoiding eating beyond satiety' (P=0.009) and 'reading food labels' (P=0.011). The NFFD diet intervention improved dietary behavior. Potential long-term clinical influence in mother and child will be investigated in further studies.