Equations to estimate human milk intake in infants aged 7 to 10 months: prediction models from a cross-sectional study.

BACKGROUND: Obtaining valid estimates of nutrient intake in infants is currently limited by the difficulties of accurately measuring human milk intake. Current methods are either unsuitable for large-scale studies (i.e., the gold standard dose-to-mother stable isotope technique) or use set amounts, regardless of known variability in individual intake. OBJECTIVES: This cross-sectional study aimed to develop equations to predict human milk intake using simple measures and to carry out external validation of existing methods against the gold standard technique. METHODS: Data on human milk intake were obtained using the dose-to-mother stable isotope technique in 157 infants aged 7-10 mo and their mothers. Predictive equations were developed using questionnaire and anthropometric data (Model 1) and additional dietary data (Model 2) using lasso regression. Bland-Altman plots and intraclass correlation coefficients (ICC) also assessed the validity of existing methods (FITS and ALSPAC studies). RESULTS: The strongest univariate predictors of human milk intake in infants of 8.3 mo on average (46% female) were infant age, infant body mass index (BMI), number of breastfeeds a day, infant formula consumption, and energy from complementary food intake. Mean [95% confidence interval (CI)] differences in predicted versus measured human milk intake [mean (SD): 762 (257) mL/day] were 0.0 mL/day (-26, 26) for Model 1 (ICC 0.74) and 0.5 mL/day (-21, 22) for Model 2 (ICC 0.83). Corresponding differences were -197 mL/day (-233, -161; ICC 0.32) and -175 mL/day (-216, -134; ICC 0.41) for the methods used by FITS and ALSPAC, respectively. CONCLUSIONS: The Human Milk Intake Level Calculation provides substantial improvements on existing methods to estimate human milk intake in infants aged 7-10 mo, while utilizing data commonly collected in nutrition surveys. Although further validation in an external sample is recommended, these equations can be used to estimate human milk intake at this age with some confidence. This clinical trial was registered at http://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=379436) as ACTRN12620000459921.

Baby Food Pouches, Baby-Led Weaning, and Iron Status in New Zealand Infants: An Observational Study.

Iron deficiency in infants can impact development, and there are concerns that the use of baby food pouches and baby-led weaning may impair iron status. First Foods New Zealand (FFNZ) was an observational study of 625 New Zealand infants aged 6.9 to 10.1 months. Feeding methods were defined based on parental reports of infant feeding at "around 6 months of age": "frequent" baby food pouch use (five+ times per week) and "full baby-led weaning" (the infant primarily self-feeds). Iron status was assessed using a venepuncture blood sample. The estimated prevalence of suboptimal iron status was 23%, but neither feeding method significantly predicted body iron concentrations nor the odds of iron sufficiency after controlling for potential confounding factors including infant formula intake. Adjusted ORs for iron sufficiency were 1.50 (95% CI: 0.67-3.39) for frequent pouch users compared to non-pouch users and 0.91 (95% CI: 0.45-1.87) for baby-led weaning compared to traditional spoon-feeding. Contrary to concerns, there was no evidence that baby food pouch use or baby-led weaning, as currently practiced in New Zealand, were associated with poorer iron status in this age group. However, notable levels of suboptimal iron status, regardless of the feeding method, emphasise the ongoing need for paying attention to infant iron nutrition.

Baby food pouches and Baby-Led Weaning: Associations with energy intake, eating behaviour and infant weight status.

Although concern is frequently expressed regarding the potential impact of baby food pouch use and Baby-Led Weaning (BLW) on infant health, research is scarce. Data on pouch use, BLW, energy intake, eating behaviour and body mass index (BMI) were obtained for 625 infants aged 7-10 months in the First Foods New Zealand study. Frequent pouch use was defined as ≥5 times/week during the past month. Traditional spoon-feeding (TSF), "partial" BLW and "full" BLW referred to the relative proportions of spoon-feeding versus infant self-feeding, assessed at 6 months (retrospectively) and current age. Daily energy intake was determined using two 24-h dietary recalls, and caregivers reported on a variety of eating behaviours. Researchers measured infant length and weight, and BMI z-scores were calculated (World Health Organization Child Growth Standards). In total, 28% of infants consumed food from pouches frequently. Frequent pouch use was not significantly related to BMI z-score (mean difference, 0.09; 95% CI -0.09, 0.27) or energy intake (92 kJ/day; -19, 202), but was associated with greater food responsiveness (standardised mean difference, 0.3; 95% CI 0.1, 0.4), food fussiness (0.3; 0.1, 0.4) and selective/restrictive eating (0.3; 0.2, 0.5). Compared to TSF, full BLW was associated with greater daily energy intake (BLW at 6 months: mean difference 150 kJ/day; 95% CI 4, 297; BLW at current age: 180 kJ/day; 62, 299) and with a range of eating behaviours, including greater satiety responsiveness, but not BMI z-score (6 months: 0.06 (-0.18, 0.30); current age: 0.06 (-0.13, 0.26)). In conclusion, neither feeding approach was associated with weight in infants, despite BLW being associated with greater energy intake compared with TSF. However, infants who consumed pouches frequently displayed higher food fussiness and more selective eating.

Adherence to Infant Feeding Guidelines in the First Foods New Zealand Study.

Infant feeding guidelines provide evidence-based recommendations to support optimal infant health, growth, and development, and exploring adherence to guidelines is a useful way of assessing diet quality. The aim of this study was to determine adherence to the recently updated Ministry of Health "Healthy Eating Guidelines for New Zealand Babies and Toddlers (0-2 years old)". Data were obtained from First Foods New Zealand, a multicentre observational study of 625 infants aged 7.0-10.0 months. Caregivers completed two 24-h diet recalls and a demographic and feeding questionnaire. Nearly all caregivers (97.9%) initiated breastfeeding, 37.8% exclusively breastfed to around six months of age, and 66.2% were currently breastfeeding (mean age 8.4 months). Most caregivers met recommendations for solid food introduction, including appropriate age (75.4%), iron-rich foods (88.3%), puréed textures (80.3%), and spoon-feeding (74.1%). Infants consumed vegetables (63.2%) and fruit (53.9%) more frequently than grain foods (49.5%), milk and milk products (38.6%), and meat and protein-rich foods (31.8%). Most caregivers avoided inappropriate beverages (93.9%) and adding salt (76.5%) and sugar (90.6%). Our findings indicated that while most infants met the recommendations for the introduction of appropriate solid foods, the prevalence of exclusive breastfeeding could be improved, indicating that New Zealand families may need more support.