Longitudinal analysis of growth trajectories in young children of Chinese-born immigrant mothers compared with Australian-born mothers living in Victoria, Australia

Early life factors that affect obesity and the need for complex solutions

The prevalence of obesity increases with age but is apparent even in early life. Early childhood is a critical period for development that is known to influence future health. Even so, the focus on obesity in this phase, and the factors that affect the development of obesity, has only emerged over the past two decades. Furthermore, there is a paucity of iterative work in this area that would move the field forward. Obesity is a complex condition involving the interplay of multiple influences at different levels: the individual and biological level, the sociocultural level, and the environmental and system levels. This Review provides a brief overview of the evidence for these factors with a focus on aspects specific to early life. By spotlighting the complex web of interactions between the broad range of influences, both causal and risk markers, we highlight the complex nature of the condition. Much work in the early life field remains observational and many of the intervention studies are limited by a focus on single influences and a disjointed approach to solutions. Yet the complexity of obesity necessitates coordinated multi-focused solutions and joined-up action across the first 2,000 days from conception, and beyond.

A cross-sectional study of infant feeding practices in Vietnamese-born mothers living in Australia

BACKGROUND

Infant feeding practices are a key modifiable risk factor for childhood overweight and obesity; and important for lifelong health and wellbeing. Despite the growing Australian immigrant population, it is unclear how infant feeding practices may differ between ethnicities living in Australia. Few studies have examined the infant feeding practices of Vietnamese mothers who migrate and give birth to infants in Australia - termed Vietnamese-born mothers. The aim of this study was to examine differences in infant feeding practices (breastfeeding, formula feeding and complementary feeding (other fluids and solids)) in Vietnamese-born mothers compared with Australian-born mothers living in Australia.

METHOD

This study analysed the Australian National Infant Feeding Survey dataset (2010-11), a large national cross-sectional survey measuring feeding practices of infants aged 0-24 months old. Infant feeding practices of Vietnamese-born mothers (n = 261) and a random sub-sample of Australian-born mothers (n = 261) were compared. Associations between ethnicity and infant feeding practices were examined through logistic and linear regression adjusting for maternal age, socioeconomic status, body mass index (BMI) at start of pregnancy, infant age at survey completion and parity. Compliance with the Australian national infant feeding guidelines was also assessed.

RESULTS

Compliance with infant feeding guidelines was low, with differences in infant feeding practices between groups. At the time of survey completion, when infants were on average 7.2 months old, compared with infants of Australian-born mothers, infants to Vietnamese-born mothers were significantly younger when first exposed to fruit juice (b = -2.41, 95%CI: -4.54- -0.28); less likely to be exposed to solids (AOR: 0.15, 95%CI: 0.05-0.44) and more likely to be exposed to formula milks (AOR: 2.21, 95%CI: 1.10-4.43); toddler milks (AOR: 16.72, 95%CI: 3.11-90.09) and fruit juice (AOR: 2.37, 95%CI: 1.06-5.32) (p < 0.05).

CONCLUSION

Low adherence with breastfeeding (low breastfeeding and high infant formula use) and other fluids (toddler milks and fruit juice) recommendations outlined by the Australian infant feeding guidelines were observed in this group of Vietnamese-born mothers. To optimise feeding and growth in Vietnamese-Australian children, culturally appropriate infant feeding support targeting breastfeeding durations, reducing reliance on infant formula, and reducing inappropriate introduction to other fluids should be the focus of infant feeding promotion within these mothers.

Determinants of rapid infant weight gain: A pooled analysis of seven cohorts

OBJECTIVE

Rapid weight gain (RWG) in infancy is strongly associated with subsequent obesity risk, but little is known about the factors driving RWG. This study explored the child and maternal factors associated with infant RWG.

METHODS

Data from seven Australian and New Zealand cohorts were used (n = 4542). Infant RWG was defined as a change in weight z-score ≥0.67 from birth to age 1 year. Univariable and multivariable logistic regression assessed the association between child and maternal factors and infant RWG in each cohort. Meta-analysis was conducted to obtain pooled effect sizes.

RESULTS

Multivariable analyses revealed boys were more likely to experience RWG (OR 1.42 95% CI 1.22, 1.66) than girls. Higher birth weight in kg (OR 0.09, 95% CI 0.04, 0.20) and gestational age in weeks (OR 0.69, 95% CI 0.48, 0.98) were associated with lower RWG risk. Children who were breastfed for ≥6 months showed lower RWG risk (OR 0.45, 95% CI 0.38, 0.53). Children of native-born versus overseas-born women appeared to have higher RWG risk (OR 1.37, 95% CI 0.99, 1.90). Maternal smoking during pregnancy increased RWG risk (OR 1.60, 95% CI 1.28, 2.01), whereas children who started solids ≥6 months (OR 0.77, 95% CI 0.63, 0.93) and children with siblings (OR 0.68, 95% CI 0.57, 0.81) showed lower RWG risk in univariable analysis, but these associations were attenuated in multivariable analysis. No association was found for maternal age, education, marital status and pre-pregnancy BMI.

CONCLUSION

Maternal country of birth, smoking status, child sex, birth weight, gestational age, infant feeding and parity were potential determinants of infant RWG.