Reproducibility and relative validity of a newly developed web-based food-frequency questionnaire for assessment of preconception diet.

BACKGROUND: The importance of diet and nutrition during preconception age is a window of opportunity to promote future parental and transgenerational health. As a sub-study to a large Norwegian study, 'Diet today - health of tomorrow', a food-frequency questionnaire (FFQ) was developed to assess diet during the preconception phase in young adults aged 20 - 30 years and in this paper we report the reproducibility and relative validity of this questionnaire. METHODS: The FFQ was developed from an existing FFQ validated in adolescents. Participants were recruited on social media and at a university. Reproducibility was assessed by comparing the test and retest of the FFQ. Relative validity was assessed by comparing intake measured by the FFQ with a 7-day weighed food record. Energy, nutrients and food intake were used to assess the reproducibility and relative validity of the FFQ. The study applied the Spearman's rank correlation coefficient, percentage of agreement and Cohen's Kappa to assess reproducibility and validity. RESULTS: There were 32 participants recruited to the study, of which 21 participants completed both the test-retest reproducibility and the relative validation. The test-retest reproducibility had a median correlation coefficient of 0.85 for energy and nutrients, a median Spearman's rank correlation coefficient of 0.75 and a median Cohen's Kappa of 0.51 for food groups. The relative validity of the FFQ had a median correlation coefficient of 0.59 for energy and nutrients, a median Spearman's rank correlation coefficient of 0.54 and a median Cohen's Kappa of 0.28 for food groups. CONCLUSION: This newly developed FFQ for preconception diet in young adults had a satisfactory test-retest reproducibility and fair relative validity.

Preeclampsia and gestational weight gain in the Norwegian Fit for Delivery trial.

OBJECTIVE: Excessive gestational weight gain is linked to risk of preeclampsia, but it is not clear whether the association is causal. The purpose of this paper was to examine gestational weight gain in the Norwegian Fit for Delivery study among women who developed preeclampsia compared to those who did not, and to further explore associations between weight gain and preeclampsia by including data on body composition (bioimpedance) assessed in the last trimester of pregnancy. RESULTS: A total of 550 women were eligible for the study. Women who developed preeclampsia gained more weight than women who did not (difference 3.7 kg, p = 0.004), with a 3.5 kg difference in total body water observed in week 36 (p = 0.040). Adjusted for age, education, pre-pregnancy body mass index (BMI), randomization, and fat mass, a one kg increase in GWG was associated with 1.3 times higher odds of preeclampsia (OR: 1.31, 95% CI 1.15-1.49, p < 0.001). An independent inverse association between fat mass in week 36 and odds of preeclampsia was observed (OR: 0.79, 95% CI 0.68-0.92, p = 0.002). Given the observed difference in total body water, these findings point to excess fluid as the component driving the association between gestational weight gain and preeclampsia in the present study. Trial registration The NFFD trial has the Clinical Trials registration: clinicaltrial.gov NCT0100168.

The effect of prenatal lifestyle intervention on weight retention 12 months postpartum: results of the Norwegian Fit for Delivery randomised controlled trial.

OBJECTIVE: To examine the effect of a prenatal lifestyle intervention on postpartum weight retention (PPWR). DESIGN: Randomised controlled trial. SETTING: Healthcare clinics in southern Norway. POPULATION: Healthy, nulliparous women with body mass index ≥19 kg/m2 , age ≥18 years, and singleton pregnancy of ≤20 gestational weeks. METHODS: Women were randomised to intervention (dietary counselling twice by phone and access to twice-weekly exercise groups during pregnancy) or control group (standard prenatal care). Intervention compliance was defined post-factum as attending dietary counselling and ≥14 exercise classes. MAIN OUTCOME MEASURES: PPWR (weight measured postpartum minus self-reported pre-pregnancy weight) and the proportion of women returning to pre-pregnancy weight. RESULTS: Of 606 women randomised, 591 were included in an intention-to-treat analysis of pregnancy outcomes and 391 (64.5%) were analysed 12 months postpartum. Mean PPWR was not significantly different between groups (0.66 kg for intervention versus 1.42 kg for control group, mean difference -0.77 kg, 95% CI -1.81, 0.28; P = 0.149). An increased proportion of intervention participants achieved pre-pregnancy weight (53% versus 43%, OR 1.50, 95% CI 1.003, 1.471; P = 0.045). However, the difference was not statistically significant when we adjusted for missing data (adjusted odds ratio (OR) 2.23, P = 0.067) using logistic mixed-effects models analysis. Women compliant with intervention had significantly lower PPWR than control participants, also after adjusting for potential confounders (adjusted mean diff -1.54 kg, 95% CI -3.02, -0.05; P = 0.039). CONCLUSIONS: The Norwegian Fit for Delivery intervention had little effect on PPWR, although women who were compliant with the intervention demonstrated significantly lower PPWR at 12 months. TWEETABLE ABSTRACT: Norwegian Fit for Delivery RCT: little effect of lifestyle intervention on weight retention 1 year postpartum.

Lifestyle intervention to limit gestational weight gain: the Norwegian Fit for Delivery randomised controlled trial.

OBJECTIVE: To examine whether a lifestyle intervention in pregnancy limits gestational weight gain (GWG) and provides measurable health benefits for mother and newborn. DESIGN: Randomised controlled trial. SETTING: Healthcare clinics of southern Norway. POPULATION: Healthy, non-diabetic, nulliparous women, aged ≥18 years, with a body mass index of ≥19 kg/m2 , and with a singleton pregnancy at ≤20 weeks of gestation. METHODS: Women were randomised to an intervention group (with dietary counselling twice by telephone and access to twice-weekly exercise groups) or to a control group (with standard prenatal care). Participants were measured three times during pregnancy and at delivery, and newborns were measured at delivery. Hospital records were reviewed for outcomes of pregnancy and delivery. Assessors were blinded to group allocation. Analysis was performed by intention to treat, assessing GWG using the Student's t-test and linear mixed models, and comparing proportions using the chi-square test. MAIN OUTCOME MEASURES: GWG, rates of pregnancy complications and operative deliveries, and newborn birthweight. RESULTS: A total of 606 women were randomised. Of these, 591 were analysed, with 296 in the intervention group and 295 in the control group. At term, the mean GWG from pre-pregnancy was 14.4 kg for the intervention group and 15.8 kg for the control group (mean difference 1.3 kg; 95% confidence interval, 95% CI 0.3-2.3 kg; P = 0.009). There was no significant difference between groups in the frequency of pregnancy complications or operative deliveries. The intervention demonstrated no effect on the mean birthweight of term infants, or on the proportion of large newborns. CONCLUSIONS: The Norwegian Fit for Delivery lifestyle intervention in pregnancy had no measurable effect on obstetrical or neonatal outcomes, despite a modest but significant decrease in GWG. TWEETABLE ABSTRACT: Norwegian Fit for Delivery RCT: reduced gestational weight gain, unchanged birthweight and obstetric outcomes.

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.