In adults, a diet low in sodium and high in potassium helps reduce blood pressure and risk of cardiovascular disease(1). Whether this same relationship exists among children is less clear. There is some evidence to indicate that reducing sodium intake is favourable for maintaining healthy blood pressure levels across childhood(2). However, it is not clear how sodium intake during childhood influences blood pressure and whether sex or body mass index moderates any effects. The effects of potassium intake and the sodium-to-potassium ratio on children’s blood pressure have been generally inconsistent(3). It is important to understand the relationship between sodium and potassium on childhood blood pressure as elevated blood pressure across childhood increases the risk of future hypertension and target organ damage(4). Few studies in children have utilised the 24-hour urinary electrolyte excretion, an objective measure, of sodium intake. Therefore, this study examined the relationship between 24-hour urinary sodium, potassium and sodium-to-potassium molar ratio and blood pressure among Australian schoolchildren aged 4–12 years; and if these associations were moderated by body weight or sex. Data from 793 children who participated in the Salt and Other Nutrient Intakes in Children study were included in this analysis. Children recruited from primary schools (n = 61) located across the state of Victoria provided one 24-hour urine collection, and anthropometric and blood pressure measurements. Blood pressure z-scores standardised for age, sex and height were calculated. Multiple linear regression analysis, with adjustment for covariates (age, sex, socioeconomic position and weight category), was conducted. Body weight (underweight/healthy weight, overweight and obese) and sex subgroup analyses, including interaction terms were completed. Mean (SD) sodium excretion was 2386 (1046) (SD) mg/d and 72% of children exceeded the recommended upper level for sodium intake. Mean (SD) potassium excretion was 1796 (675) mg/d and the sodium-to-potassium molar ratio was 2.4 (1.1). Eighteen percent of children had elevated blood pressure. Overall, there were no associations between 24-hour sodium or potassium excretion and blood pressure in adjusted regression models. However, there was a significant positive association between sodium excretion and systolic blood pressure z-score in children with obesity (b-coefficient 0.70 [95% CI 0.05, 1.33], p = 0.04, n = 23) and among girls (b-coefficient 0.09 [95% CI 0.01, 0.17], p = 0.02, n = 365). We found a positive association between 24-hr urinary excretion and SBP in girls and children living with obesity, providing further support to the hypothesis that body weight is a moderator of this relationship through heightened salt sensitivity. Public health interventions aiming to reduce elevated blood pressure during childhood are likely to be most effective by reducing sodium intake in conjunction with promoting healthy weight.

Postpartum maternal diet quality has been linked with optimal infant feeding practices. However, whether maternal diet quality during pregnancy influences infant feeding practices remains unclear. The present study explored the relationship between maternal diet quality in pregnancy and infant feeding practices in Australian women. A brief 15-item FFQ was used to collect maternal dietary data (n 469). Diet quality was calculated using a modified 2013 Dietary Guideline Index (DGI). Multivariable linear and logistic regressions with adjustment for covariates were used to examine associations between maternal diet quality in pregnancy and infant feeding practices: infant feeding mode, breast-feeding duration and timing of solids introduction. Higher DGI score during pregnancy was associated with higher odds of breast-feeding than formula/mixed feeding (adjusted OR (AOR) 1·03, 95 % CI 1·00, 1·07), longer breast-feeding duration (adjusted β 0·09, 95 % CI 0·03, 0·15) and higher odds of breast-feeding for ≥ 6 months (AOR 1·04, 95 % CI 1·02, 1·07) than for < 6 months. Associations between maternal DGI score and breast-feeding variables were moderated by maternal country of birth, with significant associations observed in Australian-born mothers only. No association was found between maternal DGI score and timing of solids introduction. Higher maternal diet quality was associated with better infant feeding practices, and the association was moderated by country of birth. Our findings provide evidence to support the initiation of dietary interventions to promote diet quality during pregnancy, particularly among Australian-born women. Further research could explore underlying mechanisms linking maternal diet quality and infant feeding practices.

Carbohydrate intake and key food sources of carbohydrates in early childhood are poorly understood. The present study described total carbohydrate intake and subtypes (i.e. starch, sugar), their primary food sources and their tracking among young Australian children. Data from children at ages 9 months (n 393), 18 months (n 284), 3·5 years (n 244) and 5 years (n 240) from the Melbourne InFANT Program were used. Three 24-hour recalls assessed dietary intakes. The 2007 AUSNUT Food Composition Database was used to calculate carbohydrates intake and food groups. Descriptive statistics summarised total carbohydrate and subtype intake and their main food sources. Tracking was examined using Pearson correlations of residualised scores between time points. Total carbohydrate, starch and sugar intakes (g/d) increased across early childhood. The percentage of energy from total carbohydrates (% E) remained stable overtime (48·4–50·5 %). From ages 9 months to 5 years, the %E from total sugar decreased from 29·4 % to 22·6 %, while the %E from starch increased from 16·7 % to 26·0 %. Sources of total carbohydrate intake changed from infant formula at 9 months to bread/cereals, fruits and milk/milk products at 18 months, 3·5 and 5 years. Across all time points, the primary sources of total sugar intake were fruit, milk/milk products and cakes/cookies, whereas main food groups for starch intake included bread/cereals, cakes/cookies and pasta. Weak to moderate tracking of total carbohydrates, total sugar and starch (g/d) was observed. These findings may have the potential to inform the refinement of carbohydrate intake recommendations and design of interventions to improve children’s carbohydrate intake.

Dietary behaviours in early childhood are understudied despite links with later health. Assessing the distribution of key food groups across the day could identify opportunities for improvements. This study aimed to describe the 24-hourly distribution of dietary intakes and frequency of eating occasions for weekdays and weekend days among children aged 18 months and assess associations of eating frequency with vegetable, fruit and discretionary intakes and zBMI. Using two parent-reported 24-h recalls of child dietary intakes from the Melbourne Infant Feeding Activity and Nutrition Trial (InFANT) Program, mean frequency of daily eating occasions and hourly intake distributions were calculated for vegetables, fruits, discretionary foods, and total foods and energy-containing beverages on weekdays (n 428) and weekend days (n 376). Multivariable regression analyses assessed associations between frequency of eating occasions, total intake of food groups and zBMI. Overall, children had 7·8 ± 1·8 (mean ± sd) eating occasions/d on weekdays, where 1·5 ± 0·8 contained vegetables, 2·2 ± 1·1 contained fruit and 2·5 ± 1·5 contained discretionary foods. Weekend day intakes were similar. Energy intakes were highest at dinner time. Intakes of total foods, fruits and discretionary foods were spread across the day (06.00–22.00). Vegetable consumption was mainly about 18.00 with minimal intake at other times. Eating frequency was associated with amount of food consumed but not consistently with zBMI. These 18-month-old children ate frequently throughout the day, with little distinction between weekdays and weekend days. Most eating occasions lacked vegetables, and frequency of discretionary foods was higher than of vegetables. Promoting vegetable consumption at occasions other than dinner could improve vegetable intake.

Despite the potential of declared serving size to encourage appropriate portion size consumption, most countries including Australia have not developed clear reference guidelines for serving size. The present study evaluated variability in manufacturer-declared serving size of discretionary food and beverage products in Australia, and how declared serving size compared with the 2013 Australian Dietary Guideline (ADG) standard serve (600 kJ). Serving sizes were obtained from the Nutrition Information Panel for 4466 packaged, discretionary products in 2013 at four large supermarkets in Sydney, Australia, and categorised into fifteen categories in line with the 2013 ADG. For unique products that were sold in multiple package sizes, the percentage difference between the minimum and the maximum serving size across different package sizes was calculated. A high variation in serving size was found within the majority of food and beverage categories – for example, among 347 non-alcoholic beverages (e.g. soft drinks), the median for serving size was 250 (interquartile range (IQR) 250, 355) ml (range 100–750 ml). Declared serving size for unique products that are available in multiple package sizes also showed high variation, particularly for chocolate-based confectionery, with median percentage difference between minimum and maximum serving size of 183 (IQR 150) %. Categories with a high proportion of products that exceeded the 600 kJ ADG standard serve included cakes and muffins, pastries and desserts (≥74 % for each). High variability in declared serving size may confound interpretation and understanding of consumers interested in standardising and controlling their portion selection. Future research is needed to assess if and how standardising declared serving size might affect consumer behaviour.

The aim of the present study was to examine the associations of sugary drink consumption and its substitution with alternative beverages with body weight gain among young children predisposed to future weight gain. Secondary analysis of the Healthy Start Study, a 1·5-year randomised controlled trial designed to prevent overweight among Danish children aged 2−6 years (n 366), was carried out. Multivariate linear regression models were used to investigate the associations of beverage consumption with change in body weight (Δweight) or BMI(ΔBMI) z-score. Substitution models were used to extrapolate the influence of replacing sugary drinks with alternative beverages (water, milk and diet drinks) on Δweight or ΔBMI z-score. Sugary drink intake at baseline and substitution of sugary drinks with milk were associated with both Δweight and ΔBMI z-score. Every 100 g/d increase in sugary drink intake was associated with 0·10 kg and 0·06 unit increases in body weight (P=0·048) and BMI z-score (P=0·04), respectively. Substitution of 100 g/d sugary drinks with 100 g/d milk was inversely associated with Δweight (β=−0·16 kg; P=0·045) and ΔBMI z-score (β=−0·07 units; P=0·04). The results of this study suggest that sugary drink consumption was associated with body weight gain among young children with high predisposition for future overweight. In line with the current recommendations, sugary drinks, whether high in added or natural sugar, should be discouraged to help prevent childhood obesity. Milk may be a good alternative to sugary drinks with regard to weight management among young obesity-predisposed children.