Healthy Diet and Pregnancy

Effect of a low-intensity 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. Because expectant mothers may be especially motivated for behavior change, pregnancy is considered a window of opportunity for public health initiatives1. In the Norwegian Fit for Delivery (NFFD) study, we developed a lifestyle intervention combining dietary advice and twice-weekly structured physical activity lessons during pregnancy, with the aim of avoiding excessive weight gain, lowering the proportion of large newborns, and improving pregnancy health in general. We evaluated the effect of the overall intervention on gestational weight gain, pregnancy complications and child neonatal health in a randomized controlled trial and found that mean weight gain was lower in the intervention group than in the control group with no difference in other outcomes2. This short paper summarizes a previous paper describing the dietary component of the intervention and how it influenced post-intervention dietary behavior3.

The diet intervention

Between 2009 and 2013 a total of 606 first-time pregnant women were recruited from 8 healthcare clinics in southern Norway in early pregnancy and randomized into receiving dietary advice and twice-weekly exercise classes for the rest of pregnancy or continued routine pregnancy care. All participants completed a questionnaire that included diet-related items at baseline before randomization.
The diet intervention was based on 10 dietary recommendations with the potential to improve energy balance-related dietary behavior and to improve diet quality in general (see below)4.
Shortly after inclusion, women in the intervention group received a pamphlet describing the 10 dietary recommendations and their simplified rationale. They were also scheduled for two telephone sessions with a trained diet advisor aiming to reinforce the dietary recommendations, and given access to a website with healthy recipes and inspirational messages. A one-evening cooking class in the University of Agder kitchen facilities was also included. The 10 dietary recommendations in the Norwegian Fit for Delivery study:

  1. Eat regular meals
  2. Drink water when thirsty
  3. Eat vegetables with dinner every day
  4. In-between meals – choose fruit and vegetables
  5. Eat sweets and snacks occasionally – only when you really appreciate it
  6. Choose small portion sizes of unhealthy foods
  7. Limit your intake of added sugar
  8. Limit your intake of salt
  9. Do not eat beyond satiety
  10. Read nutritional labels

In late pregnancy, a follow-up questionnaire on diet was completed. We developed a diet score built from 10 subscales to evaluate participant adherence to the dietary recommendations at both time points, and assessed post-intervention differences between the intervention and control group with analysis of covariance adjusted for baseline diet3.


A total of 508 women completed both questionnaires both pre- and post-intervention and were eligible for the analysis. There was no significant difference between the two groups in baseline dietary behavior or other maternal or sociodemographic characteristics. In late pregnancy, women in the intervention group (n=254) had higher overall diet score (p=0.013) and more favorable dietary behavior in 7 out of 10 dietary domains compared with the control group (n=254). Intervention women reported higher consumption of water relative to total beverage consumption (p=0.002), having vegetables with dinner more often (p=0.027), choosing fruit and vegetables for between-meal snacks more often (p=0.023), and buying small portion sizes of unhealthy foods more often than control women (p=0.010). They also limited sugar intake to a larger degree (p=0.005), avoided eating beyond satiety more often (p=0.009), and reported reading food labels more often than control women (p=0.011).

The NFFD diet intervention improved several aspects of dietary behavior. In combination with increased physical activity this contributed to lower pregnancy weight gain. The diet intervention was of relatively low intensity and could realistically be incorporated into routine pregnancy care. Considering that these women were expecting their first child, sustained dietary improvements could affect not only this first child but also their spouse and subsequent children. Potential long-term influence of the intervention on maternal and child diet and health will be investigated in further studies.

  1. Phelan S. Pregnancy: a “teachable moment” for weight control and obesity prevention. Am J Obstet Gynecol. 2010;202(2):135 e1-8.
  2. Sagedal LR, Overby NC, Bere E, Torstveit MK, Lohne-Seiler H, Smastuen M, et al. Lifestyle intervention to limit gestational weight gain: the Norwegian Fit for Delivery randomised controlled trial. BJOG : an international journal of obstetrics and gynaecology. 2017;124(1):97-109.
  3. Hillesund ER, Bere E, Sagedal LR, Vistad I, Øverby NC. Effect of a diet intervention during pregnancy on dietary behavior in the randomized controlled Norwegian Fit for Delivery study. Journal Of Developmental Origins Of Health And Disease. 2016:1-10.
  4. Overby NC, Hillesund ER, Sagedal LR, Vistad I, Bere E. The Fit for Delivery study: rationale for the recommendations and test-retest reliability of a dietary score measuring adherence to 10 specific recommendations for prevention of excessive weight gain during pregnancy. Matern Child Nutr. 2015;11(1):20-32.