Evaluation of a 2-day food record to determine iron, calcium and vitamin C intake in young Belgian women

The Reproducibility and Relative Validity of a Food Frequency Questionnaire for Identifying Iron-Related Dietary Patterns in Pregnant Women

Analyzing pregnant women’s iron intake using dietary patterns would provide information that considers dietary relationships with other nutrients and their sources. The objective of this study was to evaluate the reproducibility and relative validity of a Qualitative Food Frequency Questionnaire to identify iron-related dietary patterns (FeP-FFQ) among Mexican pregnant women. A convenience sample of pregnant women (n = 110) completed two FeP-FFQ (FeP-FFQ1 and FeP-FFQ2) and a 3-day diet record (3DDR). Foods appearing in the 3DDR were classified into the same food groupings as the FeP-FFQ, and most consumed foods were identified. Exploratory factor analysis was used to determine dietary patterns. Scores were compared (FeP-FFQ for reproducibility and FeP-FFQ1 vs. 3DDR for validity) through intraclass correlation coefficients (ICC), cross-classification, Bland−Altman analysis, and weighed Cohen kappa (κw), using dietary patterns scores tertiles. Two dietary patterns were identified: “healthy” and “processed foods and dairy”. ICCs (p < 0.01) for “healthy” pattern and “processed foods and dairy” pattern were 0.76 for and 0.71 for reproducibility, and 0.36 and 0.37 for validity, respectively. Cross-classification and Bland−Altman analysis showed good agreement for reproducibility and validity; κw values showed moderate agreement for reproducibility and low agreement for validity. In conclusion, the FeP-FFQ showed good indicators of reproducibility and validity to identify dietary patterns related to iron intake among pregnant women.

Relationship between nutrition knowledge and dietary intake

The present systematic review examined the relationship between nutrition knowledge and dietary intake in adults (mean age ≥ 18 years). Relevant databases were searched from the earliest record until November 2012. Search terms included: nutrition; diet or food knowledge and energy intake; feeding behaviour; diet; eating; nutrient or food intake or consumption. Included studies were original research articles that used instruments providing quantitative assessment of both nutrition knowledge and dietary intake and their statistical association. The initial search netted 1,193,393 potentially relevant articles, of which twenty-nine were eligible for inclusion. Most of them were conducted in community populations (n 22) with fewer (n 7) in athletic populations. Due to the heterogeneity of methods used to assess nutrition knowledge and dietary intake, a meta-analysis was not possible. The majority of the studies (65·5%: community 63·6%; athletic 71·4%) reported significant, positive, but weak (r< 0·5) associations between higher nutrition knowledge and dietary intake, most often a higher intake of fruit and vegetables. However, study quality ranged widely and participant representation from lower socio-economic status was limited, with most participants being tertiary educated and female. Well-designed studies using validated methodologies are needed to clarify the relationship between nutrition knowledge and dietary intake. Diet quality scores or indices that aim to evaluate compliance to dietary guidelines may be particularly valuable for assessing the relationship between nutrition knowledge and dietary intake. Nutrition knowledge is an integral component of health literacy and as low health literacy is associated with poor health outcomes, contemporary, high-quality research is needed to inform community nutrition education and public health policy.

Iron intake does not significantly correlate with iron deficiency among young Japanese women: a cross-sectional study

Objectives

We evaluated the association of nutrient intake with Fe deficiency with regard to lifestyle factors and health condition in young Japanese women. Uniquely among developed countries, dietary habits render Japanese populations vulnerable to Fe deficiency, owing to their relatively low intake of Fe and high intake of Fe absorption inhibitors, such as green tea and soyabeans.

Design

A cross-sectional study.

Setting and subjects

The subjects were 1019 female Japanese dietetic students aged 18–25 years. Dietary habits during the preceding month were assessed using a previously validated, self-administered, diet history questionnaire. Blood analysis was performed to assess body Fe status. Subjects were categorized with Fe deficiency when their serum ferritin levels were <12 ng/ml. Twenty-nine dietary variables, i.e. intakes of energy, sixteen nutrients including Fe and twelve food groups, were analysed using multivariate logistic regression models adjusted for possible confounders.

Results

Of the subjects, 24·5 % were categorized with Fe deficiency. However, no dietary factors assessed were significantly associated with Fe deficiency. The risk of Fe deficiency was significantly lower in women with infrequent or no menstrual cycles than in those with regular cycles (OR = 0·58; 95 % CI 0·34, 1·00) and significantly higher in women with heavy menstrual flow than in women with average flow, albeit that these were self-reported (OR = 1·83; 95 % CI 1·35, 2·48).

Conclusions

These results suggest that dietary habits, including Fe intake, do not significantly correlate with Fe deficiency among young Japanese women.

Iron intake in relation to diet and iron status of young adult women

AIMS

To determine the iron intake and food sources of iron in young adult women and to compare women with high versus low iron intake on diet and iron status.

METHODS

Iron intake and food sources were assessed by a 2-day estimated food record. Iron status was determined by a fasting venous blood sample. Differences in diet and iron status between women with high versus low iron intake were examined by comparing women of the fourth respectively first quartile of total iron intake (mg/day).

RESULTS

The median total, heme and non-heme iron intake was 10.6, 0.6 and 9.8 mg/day, respectively. The median iron intake was 93 and 131% of the estimated average requirement (EAR) of the UK (11.4 mg/day) and USA (8.1 mg/day), respectively. The most important iron intake contributors were cereals and cereal products (31%), meat and meat products (12%) and vegetables (10%). Women with a high iron intake showed a significantly higher energy-adjusted intake of alcoholic beverages and soups and a lower intake of non-alcoholic beverages than women with a low iron intake. Approximately 5% of the women had anemia, of which 3% had iron deficiency anemia (IDA). Almost 20% was iron-deficient non-anemic. In this regard, no significant differences were found between the iron intake quartiles.

CONCLUSION

The median iron intake in this study population is considerably below the national recommended dietary allowance (20 mg/day). However, based on the approach of the Dietary Guidelines Advisory Committee, iron intake seems to pose no major health problem when using the EAR as a reference. The number of women with IDA was indeed not alarming (3%), although 20% was iron-deficient non-anemic. The question remains whether an increase in iron intake can improve iron status.