Pregnancy and postpartum iron status is of great public health importance, yet few studies have examined predictors of haemoglobin (Hb) concentration during this time. We identified predictors of Hb from 24 weeks' gestation until delivery and from 4 to 25 weeks postpartum.

Blood was drawn as many as four times during care: at the initial visit, at 24–29 weeks' gestation, at delivery and postpartum. A longitudinal, multivariable linear regression model was used to predict Hb concentration.

A public health clinic in Raleigh, North Carolina.

n = 520 women who participated in the Iron Supplementation Study.

Hb concentration at the previous blood draw, short stature, non-Hispanic white ethnicity/race, > 12 years of education and smoking were positive predictors of pregnancy and postpartum Hb concentrations. Iron supplement use was a positive predictor, while inadequate weight gain and severe nausea/vomiting were negative predictors of gestational Hb. A high infant birth weight and postpartum haemorrhage were negative predictors of postpartum Hb. Pre-pregnancy body mass index had a slight positive relationship with gestational Hb, but had a strong negative relationship with postpartum Hb. The longitudinal model also confirmed the typical pattern of gestational Hb concentration. As the number of weeks between the initial visit and the 24- to 29-week visit increased, Hb at 24–29 weeks' gestation decreased. As gestational age increased from 24 weeks until delivery, Hb concentration increased as well.

The predictors identified here could be used in clinical settings to target high–risk women for intervention.

In addition to their possible direct biological effects, plasma carotenoids can be used as biochemical markers of fruit and vegetable consumption for identifying diet–disease associations in epidemiological studies. Few studies have compared levels of these carotenoids between countries in Europe.

Our aim was to assess the variability of plasma carotenoid levels within the cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC).

Plasma levels of six carotenoids – α-carotene, β-carotene, β-cryptoxanthin, lycopene, lutein and zeaxanthin – were measured cross-sectionally in 3043 study subjects from 16 regions in nine European countries. We investigated the relative influence of gender, season, age, body mass index (BMI), alcohol intake and smoking status on plasma levels of the carotenoids.

Mean plasma level of the sum of the six carotenoids varied twofold between regions (1.35μmoll−1 for men in Malmö, Sweden vs. 2.79μmoll−1 for men in Ragusa/Naples, Italy; 1.61μmoll−1 for women in The Netherlands vs. 3.52μmoll−1 in Ragusa/Naples, Italy). Mean levels of individual carotenoids varied up to fourfold (α-carotene: 0.06μmoll−1 for men in Murcia, Spain vs. 0.25μmoll−1 for vegetarian men living in the UK). In multivariate regression analyses, region was the most important predictor of total plasma carotenoid level (partial R2=27.3%), followed by BMI (partial R2=5.2%), gender (partial R2=2.7%) and smoking status (partial R2=2.8%). Females had higher total carotenoid levels than males across Europe.

Plasma levels of carotenoids vary substantially between 16 different regions in Italy, Greece, Spain, France, Germany, the UK, Sweden, Denmark and The Netherlands. Compared with region of residence, the other demographic and lifestyle factors and laboratory measurements have limited predictive value for plasma carotenoid levels in Europe.

To assess the accuracy of self-reported waist and hip circumferences and the waist-to-hip ratio (WHR) by comparison with measured waist and hip circumferences and WHR in a sample of middle-aged men and women.

Analysis of measured and self-reported waist and hip data from participants in the Oxford cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC–Oxford).

Four thousand four hundred and ninety-two British men and women aged 35–76 years.

Spearman's rank correlation coefficients between measured and self-reported waist, hip and WHR were 0.80, 0.74 and 0.44, respectively, for men and 0.83, 0.86 and 0.62 for women. Waist was underestimated, on average, by 3.1 (standard deviation (SD) 5.6) cm in men and 1.9 (SD 5.4) cm in women. The extent of underestimation was greater in participants with larger waists, older participants and women with greater body mass index (BMI). Hip was underestimated by a mean of 1.8 (SD 4.9) cm in men and 1.2 (SD 4.5) cm in women; the extent of underestimation was greater in participants with larger hip circumference and older participants. On average, WHR was underestimated by less than 2% by men and women; the extent of underestimation was greater among those with larger WHR, older people and those with greater BMI. Using self-reported values, the proportion of classification to the correct tertile was over 65% for waist and hip measurements. For WHR this proportion was 50% among men and 60% among women.

Self-reported waist and hip measurements in EPIC–Oxford are sufficiently accurate for identifying relationships in epidemiological studies.

Positive secular trends in adolescent obesity and an increased prevalence of fear of fatness, particularly among girls, have been documented world-wide. There is a lack of consensus about assessment criteria for childhood obesity and no standard exists for assessing Irish children. In 1990, the Irish National Nutrition Survey used body mass index (BMI) ≥26kgm−2 to describe the prevalence of overweight among Irish adolescents.

(1) To examine the range in classification of Dublin schoolchildren as overweight according to four standard assessment methods; (2) to assess changes in weight status, prevalence of fear of fatness and accompanying slimming practices in a one-year follow-up; and (3) to compare the prevalence of overweight with that documented in 1990 among adolescents of similar age.

A one-year follow-up study of 199 healthy schoolchildren (90 boys and 109 girls; mean age of 11 years at baseline) attending seven fee-paying (six single- and one mixed-sex) and eight non-fee-paying (four single- and four mixed-sex) primary schools in Dublin city centre.

Weight, height, waist circumference and triceps skinfold were measured and used in five definitions of overweight, including published cut-off points of BMI-for-age (Centers for Disease Control and Prevention BMI-for-age charts for boys and girls; BMI reference curves for the UK 1990; International Obesity Task Force age- and sex-specific BMI cut-offs), actual relative weight and BMI≥26kgm−2. Assessment of body image perceptions and satisfaction (using figure line drawings) was reported in a questionnaire specifically designed for this study.

The prevalence of overweight within the total group differed between the four standard definitions of weight status, by 9% at baseline and 8% at follow-up. Accordingly, increasing trends over the year ranged from zero to 3%. Using the criterion BMI≥26kgm−2, 6% of Dublin schoolchildren were overweight, compared with 1.9% of schoolchildren in 1990. Significantly more girls than boys were affected by fear of fatness and were trying to lose weight.

A standard method for assessment of weight status is urgently needed for the evaluation of obesity prevention initiatives among Irish schoolchildren. Such initiatives need to be sensitive to the pervasiveness of fear of fatness among adolescent girls.

(1) To determine the extent to which an individual's childhood social circumstances and region of residence influence their dietary pattern at age 43 years and (2) to establish the extent to which an individual adopts the dietary pattern of their social and regional circumstances at age 43 years.

Longitudinal study of a social class stratified, random sample of all legitimate, singleton births in the week of 3–9 March 1946.

England, Scotland and Wales.

The 3187 survey members who provided sociodemographic information at age 4 years in 1950 and sociodemographic and dietary data (48-hour dietary recall) at 43 years in 1989.

People who remained in the non-manual social class consumed significantly higher amounts of food items correlated with the factor health aware (items include high-fibre breakfast cereals, wholemeal breads, apples and bananas) than those who remained in the manual social class. Those who made the transition from manual social class in childhood to non-manual social class at age 43 years partly adopted the distinctive dietary patterns of the non-manual social classes. Consumption of items in the factors refined (items include whole-fat milk, white bread, sugar and butter) and sandwich (items include tomatoes, lettuce, onions, bacon and ham) did not differ by social class or regional mobility.

This work suggests that although adult dietary patterns are developed as a result of childhood influences, these patterns can be modified as a result of social and regional transitions. Such changes in dietary patterns may influence susceptibility to disease.

To highlight the differences between the food list required in a food-frequency questionnaire (FFQ) to rank people by their intake and the food items that contribute to absolute intake, and to discuss possible applications.

We conducted a nutritional survey among 1173 adults using an adapted 24-hour recall questionnaire.

To develop an FFQ, we analysed the 24-hour recall survey data by performing a stepwise multiple regression after grouping conceptually similar food items into 175 food groups.

In total, 126 food groups were included in the developed FFQ in order to explain at least 80% of the variance in the consumption of each of 27 nutrients. The nutrients that were explained by a few food groups were vitamin A (one food group), alcohol (two), β-carotene (two), vitamin E (three) and cholesterol (five). Nutrients that were explained by a large number of food groups were energy (37 food groups), potassium (31), magnesium (31), dietary fibre (30), phosphorus (31) and sodium (29). Using energy intake as an example, soft drinks were the best between-person energy classifiers, while providing only 2.4% of the total energy intake. Wine, seeds and nuts, which contributed highly to the variance, were minor energy contributors. In contrast, milk, sugar, fried chicken/turkey breast or whole chicken/turkey, which explained little of the variation in the population, were major energy contributors.

Developing an FFQ on the basis of common foods may not explain the between-person variation required for ranking individual intake in diet–disease studies. Producing lists of ‘discriminating items’ can be a useful application in developing mini-FFQs for selected nutrients.

To compare methods used to assess the validity of nutrient intake data obtained from a food-frequency questionnaire (FFQ), using folate and vitamin B12 as nutrient examples.

Cross-sectional sample from a population cohort.

Two postcode areas west of Sydney, Australia.

In total, 2895 people aged 49 years and older provided dietary data using a semi-quantitative FFQ (79% of 3654 subjects examined). The validity of the FFQ was assessed against three 4-day weighed food records (WFRs) completed by 78 people (mean age 70 years).

Folate and vitamin B12 validity data were assessed using different methods. The Spearman ranked correlations (energy-adjusted) were 0.66 for folate and 0.38 for vitamin B12. Using the Bland–Altman method, following loge transformation, no linear trend existed between the differences and means for folate and vitamin B12. Large differences existed between the FFQ and WFR in individual cases, particularly for vitamin B12. Finally, data were divided into quintile categories for the test and reference method: 79% classified folate within one quintile, 65% classified vitamin B12 within one quintile; there was no gross misclassification for folate and only 3% misclassification for vitamin B12.

Different methods of analysis provided different information about the validity of the FFQ. Correlation coefficients should not be used alone to assess the validity of nutrient data, but should be used in conjunction with Bland–Altman analyses. Depending on the use of the data, additional assessment of classification categories is recommended. This worked example demonstrates that absolute intakes of folate and vitamin B12 should be used with caution.

An adequate diet is of profound importance in infancy and early childhood. To ensure an optimal diet, knowledge about actual intake must be obtained. The aims of this study were to assess the validity of a semi-quantitative food-frequency questionnaire (SFFQ) applied in a large nation-wide survey among 2-year-old children and to examine the validity of the SFFQ in relation to different background parameters.

The SFFQ was administered to the parents close to the child's second birthday, and one to two weeks later they started to weigh and record the child's diet for 7 days.

One-hundred and eighty-seven families with a 2-year-old child completed both methods.

There were no differences between the intakes of protein, saturated fatty acids, total carbohydrates and calcium estimated from the two methods. The average intake of all micronutrients, except for calcium, was overestimated by the SFFQ. Bland–Altman plots showed a systematic increase in difference between the two methods with increasing intake for most nutrients. Spearman correlation coefficients between methods for nutrient intakes ranged from 0.26 to 0.50, the median correlation was 0.38. The correlations increased when estimates were adjusted for energy intake, the median correlation being 0.52. Differences in observed validity were found according to the number of siblings.

This study indicates that the SFFQ may be a valuable tool for measuring average intakes of energy, macronutrients and several food items among a 2-year-old population in Norway. The ability of the questionnaire to rank children according to intakes of nutrients and food items was rather low.

The food-frequency questionnaire (FFQ) can be an efficient tool to evaluate dietary intake in large, population-based studies, especially for specific foods. The objective of this study was to validate the assessment of soy and isoflavone (daidzein and genistein) intakes, measured by an FFQ, by comparing intakes with serum isoflavone concentrations.

Soy and isoflavone intakes and serum isoflavone concentrations were determined as part of a case–control study of dietary factors and risks of benign breast disease and breast cancer. The FFQ, administered during an in-person interview, included six soy-specific line items. Blood was drawn within one week of FFQ completion.

In total, 1823 women living in Shanghai, People's Republic of China.

In this population, soybean milk, fresh bean curd and other bean foods were eaten once per week, and fermented bean curd, fried bean curd puff and soybeans were eaten less than once per week. A significant linear trend (P > 0.01) in serum isoflavone concentrations across increasing categories of soy and isoflavone intakes was observed, indicating that soy and isoflavone intakes, measured by the FFQ, well distinguished serum isoflavone concentrations. Linear trends were also observed in both case and control groups in stratified analyses, suggesting little differential bias by case–control status.

The results suggest that the FFQ provides a useful marker of soy food consumption and isoflavone exposure in this population.

Most research on diet and exercise has focused on these health behaviours as proximate causes of disease, rather than examine the context of how diet and exercise are developed and maintained. This study examined religion and social support in relationship to fat intake and physical activity.

Data from surveys of 546 adults aged 17–91 years, residing in one upstate New York county, were analysed.

Most relationships between the multiple facets of religion, fat intake and physical activity were not statistically significant. After controlling for demographics and social support, Conservative Protestant women and women specifying an ‘Other’ religious affiliation reported higher fat intakes than did Catholic women. There were no relationships between religion and fat intake in men. In women, religious commitment was associated with greater moderate and vigorous physical activity, whereas in men, divine social support was associated with greater moderate physical activity. Social support did not substantially change the magnitude of the relationships between religion, diet and physical activity.

Overall, there were few relationships between religion, fat intake and physical activity, suggesting that in contemporary US society religion may play a small role in the context of how diet and exercise are developed and maintained. The limited range of religiosity in the sample, however, may have underestimated the role of religion. Significant relationships between religion and physical activity in women suggest that further research is needed to more clearly delineate religion's relationship with health behaviours.

To assess vitamin D status and the impact of three fish meals consisting of cod liver and fresh cod-liver oil on the plasma level of vitamin D metabolites in an area with high consumption of cod liver and cod-liver oil.

Experimental field study.

Thirty-two volunteers from the Skjervøy (70°N) municipality in northern Norway were recruited to consume three traditional mølje meals, consisting of cod, cod liver, fresh cod-liver oil and hard roe, in one week. The liver and fresh cod-liver oil consumed by the participants were weighed and recorded. Blood samples were collected before the first meal, and subsequently 12h and 4 days after the last meal. The blood samples were analysed for the vitamin D metabolites 25-hydroxyvitamin D (25(OH)D) and 1,25-dihydroxyvitamin D (1,25(OH)2D). All participants answered a semi-quantitative food-frequency questionnaire, which was used to estimate usual daily nutrient intake. The study was carried out in the last part of March 2001.

The median daily vitamin D intake estimated from the questionnaire was 9.9μg. The proportion of subjects with baseline 25(OH)D level below 50nmoll−1 was 15.4% and none were below 37.5nmoll−1. Only ‘mølje consumption’ and ‘time spent in daylight’ were significantly associated with baseline log 25(OH)D. The mean total intake of vitamin D in the three servings was 272μg (standard deviation 94μg), ranging from 142 to 434μg. Relative to baseline plasma concentration, the mean level of 25(OH)D decreased slightly in both post-consumption samples (P≤0.03), while 1,25(OH)2D peaked 12h after the final meal (P = 0.03).

Three mølje meals provided, on average, an amount of vitamin D equal to 54 times the recommended daily dose. Subjects with food consumption habits that included frequent mølje meals during the winter sustained satisfactory vitamin D levels in their blood, in spite of the long ‘vitamin D winter’ (i.e. absence of ultraviolet-induced vitamin D production in the skin).

To assess the prevalence and identify the predictors of food insecurity among households in Los Angeles County with incomes below 300% of the federal poverty level.

The Six-Item Short Form of the US Department of Agriculture's Household Food Security Scale was used as part of a 1999 county-wide, population-based, telephone survey.

The prevalence of food insecurity was 24.4% and was inversely associated with household income. Other independent predictors of food insecurity included the presence of children in the household (odds ratio (OR) 1.7, 95% confidence interval (CI) 1.2–2.3) and a history of homelessness in the past five years (OR 5.6, 95% CI 3.4–9.4).

Food insecurity is a significant public health problem among low–income households in Los Angeles County. Food assistance programmes should focus efforts on households living in and near poverty, those with children, and those with a history of homelessness.

To investigate the initiation of breast-feeding and exclusive breast-feeding within the first week after delivery for women in rural Vietnam.

An interviewer-administered survey was conducted on a sample of rural women who gave birth during August-October 2002.

Quang Xuong District, Thanh Hoa Province of Vietnam.

Four hundred and sixty-three women participated in the study, of whom 181 delivered at the district hospital (39.1%), 229 at a commune health centre (49.5%) and 53 at home attended by a traditional birth attendant (11.4%).

Although the initiation and exclusive breast-feeding rates were relatively high at 98.3% and 83.6% respectively, the premature introduction of complementary food was a great concern. Logistic regression analysis showed that, together with socio-cultural determinants such as feeding preferences of the husband and maternal grandmother, feeding practices of friends, factors relating to delivery methods, delivery locations and health problems could influence the initiation rate and breast-feeding patterns.

To promote breast-feeding practices of rural mothers, health education on breast-feeding should take into account local socio-cultural features in addition to improving the counselling skills of health workers.

(1) To identify the major sources of nutrition information, and the perceived credibility thereof, among urban black South African women; and (2) to determine the level of knowledge regarding nutrition, particularly regarding the topic of obesity.

A cross–sectional descriptive study that was both qualitative (focus groups) and quantitative (individual questionnaires). Three hundred and ninety–four black women aged 17–49 years were conveniently sampled from the Western Cape and Gauteng provinces in South Africa.

Four focus groups were held with 39 women to identify common themes relating to nutrition knowledge. Based on these data, a questionnaire instrument was developed and administered to 394 women by trained fieldworkers.

The most frequently encountered source of nutrition information was the media, particularly the radio and TV (73.4% and 72.1% of subjects, respectively, obtained information from this source in the past year), followed by family/friends (64.6%). Despite only 48.5% of subjects having received nutrition information from a health professional, this was the most highly credible information source. Factors being most influential in choice of foods were taste, preferences of the rest of the family, and price. A lack of knowledge on certain aspects of nutrition was identified, as well as misconceptions regarding diet and obesity.

To improve nutrition knowledge and the effectiveness of nutrition education activities in South Africa, it is recommended that health and nutrition educators become more actively involved with the training of health professionals, particularly those engaged in delivery of services at primary care level, and in turn encourage health professionals to engage more with media sources. Nutrition messages delivered from health professionals via the media will enable public exposure to nutrition information which is not only easily accessible but also perceived to be highly credible.

There is a paucity of data on the micronutrient status of low-income, lactating South African women and their infants under 6 months of age. The aim of this study was to elucidate the level of anaemia and vitamin A deficiency (VAD) in peri-urban breast-feeding women and their young infants.

Cross-sectional study including anthropometric, biochemical and infant feeding data.

Peri-urban settlement in Cape Town, South Africa.

Breast-feeding women (n = 113) and their infants (aged 1–6 months) attending a peri-urban clinic.

Mean (standard deviation (SD)) haemoglobin (Hb) of the lactating mothers was 12.4 (1.3) gdl−1, with 32% found to be anaemic (Hb < 12 g dl−1). Maternal serum retinol was 49.8 (SD 13.3) μg dl−1, with 4.5% VAD. Using breast milk, mean (SD) retinol concentration was found to be 70.6 (24.6) μg dl−1 and 15.7 (8.3) μg/g milk fat, with 13% below the cut-off level of <8μg/g fat. There was no correlation found between breast milk retinol and infant serum retinol. Z-scores (SD) of height-for-age, weight-for-age and weight-for-height were –0.69 (0.81), 0.89 (1.01) and 1.78 (0.83), respectively. Mean (SD) infant Hb was 10.9 (1.1) g dl−1, with the prevalence of anaemia being 50%, 33% and 12% using Hb cut-offs below 11 g dl−1, 10.5 g dl−1 and 9.5 g dl−1, respectively. Mean (SD) infant serum retinol was 26.9 (7.2) μg dl−1, with 10% being VAD. None of the infants was exclusively breast-fed, 22% were predominantly breast-fed and 787percnt; received complementary (mixed) breast-feeding. Thirty-two per cent of infants received weaning foods at an exceptionally young age (≤1 month old).

A high rate of anaemia is present in lactating women residing in resource-poor settings. Moreover, their seemingly healthy infants under 6 months of age are at an elevated risk of developing early-onset anaemia and at lower risk of VAD.