Relative validity of a semi-quantitative, web-based FFQ used in the 'Snart Forældre' cohort - a Danish study of diet and fertility.

OBJECTIVE: To assess the relative validity of a semi-quantitative, web-based FFQ completed by female pregnancy planners in the Danish 'Snart Forældre' study. DESIGN: We validated a web-based FFQ based on the FFQ used in the Danish National Birth Cohort against a 4 d food diary (FD) and assessed the relative validity of intakes of foods and nutrients. We compared means and medians of intakes, and calculated Pearson correlation coefficients and de-attenuated coefficients to assess agreement between the two methods. We also calculated the proportion correctly classified based on the same or adjacent quintile of intake and the proportion of grossly misclassified (extreme quintiles). SETTING: Participants (n 128) in the 'Snart Forældre' study who had completed the web-based FFQ were invited to participate in the validation study. SUBJECTS: Participants in the 'Snart Forældre' study, in total ninety-seven women aged 20-42 years. RESULTS: Reported intakes of dairy products, vegetables and potatoes were higher in the FFQ compared with the FD, whereas reported intakes of fruit, meat, sugar and beverages were lower in the FFQ than in the FD. Overall the de-attenuated correlation coefficients were acceptable, ranging from 0·33 for energy to 0·93 for vitamin D. The majority of the women were classified in the same or adjacent quintile and few women were misclassified (extreme quintiles). CONCLUSION: The web-based FFQ performs well for ranking women of reproductive age according to high or low intake of foods and nutrients and, thus, provides a solid basis for investigating associations between diet and fertility.

What do Danish children eat, and does the diet meet the recommendations? Baseline data from the OPUS School Meal Study.

A child's diet is an important determinant for later health, growth and development. In Denmark, most children in primary school bring their own packed lunch from home and attend an after-school care institution. The aim of the present study was to evaluate the food, energy and nutrient intake of Danish school children in relation to dietary guidelines and nutrient recommendations, and to assess the food intake during and outside school hours. In total, 834 children from nine public schools located in the eastern part of Denmark were included in this cross-sectional study and 798 children (95·7 %) completed the dietary assessment sufficiently (August-November 2011). The whole diet was recorded during seven consecutive days using the Web-based Dietary Assessment Software for Children (WebDASC). Compared with the food-based dietary guidelines and nutrient recommendations, 85 % of the children consumed excess amounts of red meat, 89 % consumed too much saturated fat, and 56 % consumed too much added sugar. Additionally 35 or 91 % of the children (depending on age group) consumed insufficient amounts of fruits and vegetables, 85 % consumed insufficient amounts of fish, 86 % consumed insufficient amounts of dietary fibre, 60 or 84 % had an insufficient Fe intake (depending on age group), and 96 % had an insufficient vitamin D intake. The study also showed that there is a higher intake of fruits and bread during school hours than outside school hours; this is not the case with, for example, fish and vegetables, and future studies should investigate strategies to increase fish and vegetable intake during school hours.

Maternal dietary glycaemic load during pregnancy and gestational weight gain, birth weight and postpartum weight retention: a study within the Danish National Birth Cohort.

Dietary glycaemic index and glycaemic load (GL) have been related to obesity and other health outcomes. The objective of the present study was to examine the associations between maternal dietary GL and gestational weight gain, birth weight, the risk of giving birth to a child large-for-gestational age (LGA) or small-for-gestational age and postpartum weight retention (PPWR). Data were derived from the Danish National Birth Cohort (1996-2002), including data on gestational and lifestyle factors in pregnancy and 18 months postpartum. Dietary data were collected using a validated FFQ. Information on birth outcome was obtained through registers. A total of 47,003 women were included. The associations between the GL and birth outcome, gestational weight gain, assessed between weeks 12 and 30 of gestation, and PPWR were analysed by linear and logistic regression. Birth weight increased by 36 g from the lowest to highest GL quintile (95% CI 19, 53 g), and an increased risk of LGA of 14% was detected in the highest GL quintile compared with the lowest GL quintile. Among normal-weight and overweight women, higher gestational weight gain rates were detected in the highest GL quintile (26 g/week (95% CI 19, 34) and 30 g/week (95% CI 13, 46), respectively). The association between the GL and PPWR was most pronounced among pre-pregnant obese women, with an increase in weight retention of 1·3 (95% CI 0·2, 2·8) kg from the lowest to highest GL quintile. The GL may play a role for excessive gestational weight gain and PPWR, which may be more pronounced among overweight and obese women.

Evaluation of dietary intake in Danish adults by means of an index based on food-based dietary guidelines.

BACKGROUND: Data on dietary intake and physical activity has been collected from a representative sample of the Danish population from 2003-2008. OBJECTIVES: The aim of the present study was to describe the habitual diet in Denmark and to evaluate the overall diet quality using a diet quality index based on the National Food-Based Dietary Guidelines (FBDG), which consists of seven guidelines regarding diet and one regarding physical activity. DESIGN: Data from the Danish National Survey of Diet and Physical Activity 2003-2008 (n=3354) were included. The diet quality index was constructed based on five of the seven dietary guidelines. Individuals were categorised according to quartiles of the diet quality index, and food and nutrient intakes were estimated in each of the groups. RESULTS: Macronutrient distribution did not meet recommendations in any of the groups, as energy from total fat and especially saturated fat was too high. A high intake of high-fat milk products, fat on bread and processed meat contributed to a high intake of total fat and saturated fat, and sugar-sweetened soft drinks contributed to a high intake of added sugars in the group below the lowest quartile of the diet quality index. Individuals above in the highest quartile had higher intakes of 'healthy foods' such as fish, fruit and vegetables, rye bread, and also a higher consumption of water and wine. Overall, intakes of micronutrients were sufficient in all groups. CONCLUSIONS: The diet quality index is a useful tool in assessing food and nutrient intake in individuals with high vs. low degree of compliance towards the dietary guidelines, and provides a valuable tool in future studies investigating variations in dietary intakes with respect to lifestyle, demographic and regional differences in Denmark.

Relative validity of the pre-coded food diary used in the Danish National Survey of Diet and Physical Activity.

OBJECTIVE: To determine the relative validity of the pre-coded food diary applied in the Danish National Survey of Dietary Habits and Physical Activity. DESIGN: A cross-over study among seventy-two adults (aged 20 to 69 years) recording diet by means of a pre-coded food diary over 4 d and a 4 d weighed food record. Intakes of foods and drinks were estimated, and nutrient intakes were calculated. Means and medians of intake were compared, and cross-classification of individuals according to intake was performed. To assess agreement between the two methods, Pearson and Spearman's correlation coefficients and weighted kappa coefficients were calculated. SETTING: Validation study of the pre-coded food diary against a 4 d weighed food record. SUBJECTS: Seventy-two volunteer, healthy free-living adults (thirty-five males, thirty-seven females). RESULTS: Intakes of cereals and vegetables were higher, and intakes of fruit, coffee and tea were lower, in the weighed food record compared with the food diary. Intakes of nutrients were grossly the same in the two methods, except for protein, where a higher intake was recorded in the weighed record. In general, moderate agreement between the two methods was found. CONCLUSIONS: Participants were classified moderately correct according to food and nutrient intakes assessed in the pre-coded food diary; however values of absolute food intakes should be used and interpreted with caution. Improvement of the methods to estimate portion size may increase the accuracy of the dietary intake estimates.

Associations of maternal fish intake during pregnancy and breastfeeding duration with attainment of developmental milestones in early childhood: a study from the Danish National Birth Cohort.

BACKGROUND: Few studies have examined the overall effect of maternal fish intake during pregnancy on child development or examined whether the developmental benefits of maternal fish intake are greater in infants breastfed for a shorter duration. OBJECTIVE: We aimed to study associations of maternal prenatal fish intake and breastfeeding duration with child developmental milestones. DESIGN: We studied 25 446 children born to mothers participating in the Danish National Birth Cohort, a prospective population-based cohort study including pregnant women enrolled between 1997 and 2002. Mothers reported child development by a standardized interview, which we used to generate developmental scores at ages 6 and 18 mo. We used multivariate cumulative ordinal logistic regression to evaluate the odds of higher developmental scores associated with maternal fish intake and breastfeeding, after adjustment for child age, sex, and growth; maternal size and pregnancy characteristics; and parental education and social status. RESULTS: Higher maternal fish intake and greater duration of breastfeeding were associated with higher child developmental scores at 18 mo [odds ratio: 1.29 (95% CI: 1.20, 1.38) for the highest versus the lowest quintile of fish intake, and 1.28 (1.18, 1.38) for breastfeeding for > or =10 mo compared with breastfeeding for < or =1 mo]. Associations were similar for development at 6 mo. Associations of fish intake with child development did not differ by breastfeeding duration. CONCLUSIONS: Maternal fish intake during pregnancy and the duration of breastfeeding are independently associated with better early child development. Future research and consumption guidelines, incorporating nutritional benefits as well as contaminant risks, should consider the overall effect of prenatal fish consumption on child development.

Association between a Mediterranean-type diet and risk of preterm birth among Danish women: a prospective cohort study.

BACKGROUND: Thus far, few factors with a causal relation to preterm birth have been identified. Many studies have focused on the woman's diet, but most have been discouraging. The aim of the present study was to examine if maternal intake of a Mediterranean-type diet (MD) is associated with reduced risk of preterm birth. METHODS: The Danish National Birth Cohort assessed diet in mid-pregnancy by food frequency questionnaires (FFQ). Women consuming MD were those who ate fish twice a week or more, used olive or rape seed oil, consumed 5+ fruits and vegetables a day, ate meat (other than poultry and fish) at most twice a week, and drank at most 2 cups of coffee a day. RESULTS: Of 35,530 non-smoking women, 1,137 (3.2%) fulfilled all MD criteria, and 540 (1.5%) none. Odds ratios for preterm birth and early preterm birth were 0.61 (95% Confidence Interval (CI): 0.35-1.05) and 0.28 (0.11-0.76), respectively, in MD women compared to women fulfilling none of the MD criteria. CONCLUSION: Shifting towards a MD during pregnancy may reduce the risk of early delivery in Danish women.

Milk consumption during pregnancy is associated with increased infant size at birth: prospective cohort study.

BACKGROUND: Cow milk contains many potentially growth-promoting factors. OBJECTIVE: The objective was to examine whether milk consumption during pregnancy is associated with greater infant size at birth. DESIGN: During 1996-2002, the Danish National Birth Cohort collected data on midpregnancy diet through questionnaires and on covariates through telephone interviews and ascertained birth outcomes through registry linkages. Findings were adjusted for mother's parity, age, height, prepregnant BMI, gestational weight gain, smoking status, and total energy intake; father's height; and family's socioeconomic status The analyses included data from 50,117 mother-infant pairs. RESULTS: Mean (+/-SD) consumption of milk was 3.1 +/- 2.0 glasses/d. Milk consumption was inversely associated with the risk of small-for gestational age (SGA) birth and directly with both large-for-gestational age (LGA) birth and mean birth weight (P for trend < 0.001). In a comparison of women drinking >or=6 glasses/d with those drinking 0 glasses/d, the odds ratio for SGA was 0.51 (95% CI: 0.39, 0.65) and for LGA was 1.59 (1.16, 2.16); the increment in mean birth weight was 108 g (74, 143 g). We also found graded relations (P < 0.001) for abdominal circumference (0.52 cm; 0.35, 0.69 cm), placental weight (26 g; 15, 38 g), birth length (increment: 0.31 cm; 0.15, 0.46 cm), and head circumference (0.13 cm; 0.04, 0.25 cm). Birth weight was related to intake of protein, but not of fat, derived from milk. CONCLUSION: Milk intake in pregnancy was associated with higher birth weight for gestational age, lower risk of SGA, and higher risk of LGA.

Iron supplement use among Danish pregnant women.

OBJECTIVES: To evaluate compliance with the national recommendation on supplemental iron to all pregnant women in Denmark and to explore differences between compliers and non-compliers with respect to dietary habits and other lifestyle factors. DESIGN: Intake of supplemental iron from pure iron supplements and from multivitamin and mineral preparations was estimated in mid-pregnancy. SETTING: Nationwide cohort study, the Danish National Birth Cohort (DNBC), comprising more than 100,000 women recruited in early pregnancy. SUBJECTS: Information on diet and dietary supplements was available for 54,371 women. Of these, information on lifestyle factors was available for 50,902 women. RESULTS: A high compliance with the recommendation was found, as approximately 77% of the women reported use of iron supplements during pregnancy. However, many of the compliers did not obtain the recommended doses of iron, which can partly be explained by the lack of iron preparations of appropriate doses available on the Danish market. Compliance with the recommendation was associated with age above 20 years, primiparity, body mass index<30 kg m- 2, non-smoking and long education. No major differences were seen in dietary intake between compliers and non-compliers.ConclusionOverall, a high compliance rate was found among participants of the DNBC but a clarification on daily dose is needed, and more concern should be paid to vulnerable groups such as young, smoking women and women with no or short education.

Association between fruit and vegetable consumption and birth weight: a prospective study among 43,585 Danish women.

OBJECTIVE: To examine whether fruit and vegetable consumption in pregnancy is associated with birth weight in a Western population. DESIGN: Prospective cohort study based on telephone interviews, a food frequency questionnaire (FFQ), and extractions of birth characteristics from national health registries. SUBJECTS AND SETTING: The 43,585 Danish women from the Danish National Birth Cohort who had completed the FFQ in mid-pregnancy and on whom information about birth outcome was available. The exposures were frequency of green leafy vegetable (GLV) intake and quantified intake of fruit, fruit and vegetables, and fruit and vegetables and juice. The outcomes were birth weight and z-score for expected birth weight adjusted for sex and gestation week. Information on maternal height, weight, smoking, and other potential confounders was obtained through telephone interviews. RESULTS: Significant associations were found for all exposures to fruit and vegetable intake with birth weight and most with z-score. The strongest association was found for fruit intake in which case birth weight increased by 10.7 g (95% CI 7.3-14.2) per quintile. All associations were stronger among lean women (BMI<20, n = 7,169), whose children's birth weight increased by 14.6 g (95% CI 6.4-22.9) per quintile increase in fruit intake. For GLV the results were more inconclusive. When adjusted for confounders, but not for energy, the association between GLV and birth weight was significant, but the same was not the case for z-score. CONCLUSION: Fruit and vegetable consumption in pregnancy is positively associated with birth weight in well-nourished Danish women, especially among lean women.

Low compliance with recommendations on folic acid use in relation to pregnancy: is there a need for fortification?

OBJECTIVE: As a means to prevent neural tube defects (NTDs), women planning pregnancy in Denmark are recommended to take a dietary supplement of 400 microg folic acid daily during the periconceptional period. We examined compliance with this recommendation in a national survey. DESIGN: Cohort study on pregnant women in Denmark. SETTING: The Danish National Birth Cohort (DNBC). SUBJECTS: From November 2000 to February 2002, 22,000 pregnant women were recruited for DNBC. Use of dietary supplements was recorded at enrollment. Compliance with the recommendation was related to an information campaign that took place during the second half of 2001, and to lifestyle factors provided in a telephone interview by the end of the first trimester of pregnancy. RESULTS: An increase was seen in the proportion of women complying with the recommendation in the study period and this coincided with the information campaign events. However, even at the end of the period, only 22.3% of the women who had planned their pregnancy fully complied with the recommendation. No increase at all was seen in periconceptional folic acid use among women with unplanned pregnancies. Young age, low education and smoking were identified as factors that determined non-compliance. CONCLUSIONS: Alternative and more effective strategies are needed if the Danish population is to benefit fully from the knowledge that folic acid prevents NTDs. Future strategies should not only target vulnerable groups, such as the less educated and the young, but also women who get pregnant without planning this. The only possible way to reach the last group may be through fortification of foods with folic acid.

Use of dietary supplements in Denmark is associated with health and former smoking.

OBJECTIVES: To describe the use of dietary supplements in a group of Danish adults and to investigate the differences between users and non-users with respect to age, gender, health and lifestyle factors. DESIGN: Cross-sectional study in two Danish cities. SETTING: The Danish Investigation on Iodine Intake and Thyroid Diseases, 1997-1998. SUBJECTS: Participants were 3707 women (selected age groups between 18 and 65 years) and 942 men (60-65 years). Participation rate was 50%. Supplement data were collected in a personal interview. Data on education, smoking, alcohol intake, physical activity, use of medication and self-perceived health were derived from a self-administered questionnaire. Multiple logistic regression was used for the statistical analysis. RESULTS: Participants were asked about all kinds of supplements, ranging from products containing vitamins and minerals, to fish oils and products of herbal origin. On average 59% reported use of some kind of dietary supplement. Most common were combined multivitamin/mineral products (48%) followed by single vitamin C products (10%). Twelve per cent used three or more different supplements. Supplement use was strongly associated with age and gender, being highest among elderly women (78%). Ex-smokers were more likely to use supplements than subjects who had never smoked (odds ratio (OR) 1.36, 95% confidence interval (CI) 1.09-1.76). Supplement use was more likely among subjects who had many days of illness 95% CI 1.12-1.66) and among users of medication 95% CI 1.04-1.42). Subjects who perceived their health as poor were more likely to use supplements other than just a multivitamin/mineral tablet 95% CI 1.31-3.77). CONCLUSIONS: Use of dietary supplements was related to age, gender and smoking, but also to poor self-perceived health status and absence from work. This indicates that a group of people use supplements as a form of self-medication.