Bioavailability of Australian pre-schooler iron intakes at specific eating occasions is low.

PURPOSE: Poor bioavailability may contribute to iron deficiency among children in high-resource countries, but iron bioavailability of Australian pre-schooler diets is unknown. This study aimed to estimate the bioavailability of Australian pre-schooler iron intakes across the day and by eating occasions to identify optimal timing for intervention, by using five previously developed algorithms, and to estimate the proportion of children with intakes of absorbable iron below the requirements. METHODS: Dietary data of children aged 2 to < 6 y (n = 812) from the 2011-12 National Nutrition and Physical Activity Survey were collected via two 24-h recalls. Usual food and nutrient intakes were estimated via Multiple Source Method. Phytate, polyphenol, and heme iron values were sourced from international databases or the literature. Five previously published algorithms were applied to observed dietary data to estimate iron bioavailability and calculate the prevalence of children with intakes of absorbable iron below requirements. RESULTS: Pre-schooler daily iron bioavailability was low (2.7-10.5%) and corresponded to intakes of 0.18-0.75 mg/d of absorbable iron. The proportion of children with inadequate intakes of absorbable iron ranged between 32 and 98%. For all eating occasions, dinner offered iron of the greatest bioavailability (4.2-16.4%), while iron consumed at breakfast was of the lowest bioavailability (1.2-5.6%). CONCLUSION: Future strategies are required to improve intakes of bioavailable iron for pre-schoolers to prevent the risk of deficiency. These strategies could include the encouragement of concomitant consumption of enhancers of iron absorption with iron-rich sources, particularly at breakfast.

Breastfeeding and the Longitudinal Changes of Body Mass Index in Childhood and Adulthood: A Systematic Review.

Mounting evidence supports the beneficial role of breastfeeding in lowering obesity risk, but the enduring impact of breastfeeding on longitudinal changes in body mass index (BMI) (i.e., BMI trajectories) remains unclear. This systematic review summarized evidence on how breastfeeding influenced the longitudinal trajectories of BMI later in life. Literature searches were conducted in Medline, Embase, Web of Science, and ScienceDirect to identify studies that assessed how breastfeeding (versus other feeding types or duration) was associated with longitudinal trajectories of BMI or BMI z-score. Three randomized controlled trials (RCTs) and 24 longitudinal cohort studies were included. Two-thirds (18/27) of studies were rated as acceptable or high quality. Most cohort studies (9/11) showed that children who continued to breastfeed at 3 to 12 mo of age had a lower BMI trajectory or lower odds of following a high BMI trajectory than those who were formula-fed or mixed-fed. The BMI differences between breastfeeding and other feeding groups were evident from age 7 mo and remained up to 8 y, and the magnitude of between-group BMI differences increased with age. For breastfeeding duration, 12 out of 15 cohort studies found that longer breastfeeding duration was associated with lower BMI trajectories up to age 18 y. Moreover, beneficial associations were observed for both exclusive and any breastfeeding with BMI trajectory. In contrast, mixed findings were reported from 3 RCTs that compared BMI trajectories from birth to ages 12 to 24 mo between breastfeeding promotion versus control or breastfeeding versus formula-feeding groups. The current review provides further longitudinal evidence from cohort studies that breastfeeding versus formula/mixed feeding or longer breastfeeding duration was associated with lower BMI trajectories. Such associations initiated in early childhood became more apparent with age and were sustained into early adulthood. The existing evidence substantiates the importance of breastfeeding promotion and continuation to support obesity prevention.

Iron Nutrition of Pre-Schoolers in High-Income Countries: A Review.

Pre-schoolers are vulnerable to iron deficiency, which, in high-resource countries, is mainly caused by suboptimal or poorly absorbable iron intakes. This review examines the prevalence of inadequate iron intakes and status, and the non-dietary factors associated with these, among children aged between 2 and 5 years within high-income countries. It then considers the quality of the pre-schooler diet in terms of dietary factors, dietary patterns, and iron intakes. Additionally, it discusses the assessment of iron bioavailability and examines the various methods used to estimate the amount of absorbable iron in pre-schooler diets. Knowledge of the adequacy of iron intakes and bioavailability of iron intakes, and dietary patterns associated with iron intakes can facilitate the design and implementation of effectively targeted community-based intervention studies to improve iron intakes and iron bioavailability to minimise the risk of iron deficiency.

Dietary patterns of Australian pre-schoolers and associations with haem and non-haem iron intakes.

PURPOSE: To describe Australian pre-schooler dietary patterns and examine their associations with dietary iron intakes. METHODS: Dietary data of children (n = 812, 2 to < 6 years old) from the 2011-12 National Nutrition and Physical Activity Survey were collected via two non-consecutive 24-h recalls and analysed using AUSNUT 2011-13. Usual food and nutrient intakes were estimated via Multiple Source Method. Principal component analysis was used to extract dietary patterns from 32 food groups. Associations between dietary patterns and energy-adjusted iron intakes were assessed using linear regression, accounting for the complex survey design. RESULTS: Mean (SD) usual total dietary and haem iron intakes were 6.3 (1.9) and 0.5 (0.3) mg/day, respectively. Three dietary patterns were identified, explaining 14% of the variance. Pattern 1 (positive loadings for cheese, breads, fats and oils, and water) was positively associated with total dietary iron intakes (ß = 0.08, 95% CI 0.01, 0.15). Pattern 3 (positive loadings for red meat, fortified fruit and vegetable products, and sauces and spreads) was negatively associated with total dietary iron (ß = - 0.08, 95% CI - 0.14, - 0.01) and non-haem iron (ß = - 0.09, 95% CI - 0.15, - 0.02) intakes. No dietary patterns were associated with haem iron intakes. CONCLUSIONS: Three main patterns characterise Australian pre-schooler diets. The pattern with which dietary iron is positively associated is predominately characterised by non-haem iron sources and non-iron-fortified foods. Future research is required to estimate the iron bioavailability of Australian pre-schooler diets.

Adequacy of iron intakes and socio-demographic factors associated with iron intakes of Australian pre-schoolers.

PURPOSE: To estimate the prevalence of inadequate iron intakes and identify socio-demographic factors associated with iron intakes of Australian children aged 2-5 years. METHODS: Data from the 2011-2012 National Nutrition and Physical Activity Survey component of the Australian Health Survey were analysed (n = 783, 2-5 years old). Dietary intake was assessed via two non-consecutive 24-h recalls. Prevalence of inadequate iron intake was estimated using the full probability approach after estimating the distribution of usual intakes with PC-SIDE. Associations between potential socio-demographic factors and energy-adjusted iron intakes were assessed via linear regression accounting for the complex survey design. RESULTS: Mean (SD) iron intakes for pre-schoolers were 7.9 (1.9) mg/day and the prevalence of inadequate iron intake was 10.1% (95% CI 7.9%, 12.1%). Male sex (mean difference between boys and girls: - 0.22 (95% CI - 0.03, - 0.41) mg/day; p = 0.022) and age (each additional year was associated with 0.11 (95% CI - 0.22, - 0.00) mg/day lower iron intake; p = 0.048) were negatively associated with pre-schooler iron intakes. CONCLUSIONS: This study provides current data relating to the iron nutrition of Australian pre-schoolers. Poor iron intakes continue to be a problem for 10% of Australian children beyond the second year of life, with iron intakes being lower for boys compared to girls and declining with age. Future research should examine strategies to improve iron intakes of young children, with a focus on promoting iron-rich food sources.

Iron intakes of Australian infants and toddlers: findings from the Melbourne Infant Feeding, Activity and Nutrition Trial (InFANT) Program.

Fe deficiency remains the most common nutritional deficiency worldwide and young children are at particular risk. Preventative food-based strategies require knowledge of current intakes, sources of Fe, and factors associated with low Fe intakes; yet few data are available for Australian children under 2 years. This study's objectives were to determine intakes and food sources of Fe for Australian infants and toddlers and identify non-dietary factors associated with Fe intake. Dietary, anthropometric and socio-demographic data from the Melbourne Infant Feeding, Activity and Nutrition Trial Program were analysed for 485 infants (mean age: 9·1 (sd 1·2) months) and 423 toddlers (mean age: 19·6 (sd 2·6) months) and their mothers. Dietary intakes were assessed via 24-h recalls over 3 non-consecutive days. Prevalence of inadequate Fe intake was estimated using the full probability approach. Associations between potential non-dietary predictors (sex, breast-feeding status, age when introduced to solid foods, maternal age, maternal education, maternal employment status and mother's country of birth) and Fe intakes were assessed using linear regression. Mean Fe intakes were 9·1 (sd 4·3) mg/d for infants and 6·6 (sd 2·4) mg/d for toddlers. Our results showed that 32·6 % of infants and 18·6 % of toddlers had inadequate Fe intake. Main food sources of Fe were Fe-fortified infant formula and cereals for infants and toddlers, respectively. Female sex and current breast-feeding were negatively associated with infant Fe intakes. Introduction to solid foods at or later than 6 months was negatively associated with Fe intake in toddlers. These data may facilitate food-based interventions to improve Australian children's Fe intake levels.