Associations of home environment, food and growth among Pacific children in Auckland, New Zealand
Pacific adults and children in New Zealand have the highest prevalence of obesity and overweight compared with any other group. The relationships of home environments with food consumption and rapid growth among Pacific children residing in South Auckland, New Zealand are not well understood. These factors were examined in the Pacific Islands Families (PIF) birth cohort study, which started in the year 2000 with the last wave of physical measurements in 2014. At recruitment, participant families (n=1376) were representative of the Pacific population in South Auckland, an area where 37% of Pacific people in New Zealand reside. As well as birth weight, anthropometric measurements were recorded for PIF children followed up at 4, 6, 9, 11 and 14 years (y). Examination of growth trajectory to age 14 y confirmed that the child cohort continued to grow at an accelerated rate compared to the World Health Organisation (WHO) child growth reference. The increase in mean BMI among PIF boys and girls from 11 to 14y was 77% and 108% higher than the WHO references. The prevalence of overweight including obesity was 78.1% for boys and 71.8% for girls at mean age 14.5 years using the International Obesity Task Force reference. Analysis of food frequency patterns at ages 4 and 6 y highlighted 12 most frequently eaten foods accounting for 25% of all food consumed on a daily basis. Average frequency of consumption of these 12 foods remained relatively stable over this period of transition to school (r2 = 0.53). Three carbohydrate foods, bread, breakfast cereal and rice, were the most frequently eaten, followed by milk and fruit (apples and pears, oranges and mandarins, and bananas). Snack foods, including powdered fruit drinks, crisps, noodles, and food drinks (e.g. Milo™) constituted a third of the most frequently eaten foods and chicken was the only protein in the most frequently eaten foods. At age 9 years for 972 children, small positive associations of household size and daily intake of bread (rho=0.138, p<0.001) and weekly intake of soft drink (rho=0.088, p<0.05), and a negative association of household size and BMI Z among girls (rho=-0.099, p<0.05) were found. Two-parent status was positively associated with BMI Z (rho=0.084, p<0.05) and maternal education was positively associated with fast food intake (rho=0.106, p<0.05) and negatively with BMI Z (rho=-0.086, p<0.05). Maternal deprivation was positively associated with higher consumption of bread (rho=0.213, p<0.01), fast food (rho=0.108, p<0.05) and soft drink (rho=0.111, p<0.05) and negatively associated with fruit (rho=-0.094, p<0.01) and vegetables (rho=-0.094, p<0.001). Two styles of parenting, authoritative and authoritarian, were found to have acceptable internal reliability (0.8 > α ≥ 0.7), allowing further examination against food habits and BMI Z. Described simply, authoritative parenting practices are highly controlled yet highly nurturing styles of parenting. Whereas authoritarian parenting practices encompass highly controlled but low nurturing styles of parenting. Authoritative parenting was significantly positively associated with daily consumption of fruit (rho=0.129, p<0.001) and vegetables (rho=0.082, p<0.05) among boys and girls, and with bread (rho=0.119, p<0.05) but only among girls. Authoritative parenting was also significantly negatively associated with consumption of fast food (rho=-0.186, p<0.001) and soft drink (rho=-0.094, p<0.01). Authoritative parenting was negatively associated with overall BMI Z. Alternatively, authoritarian parenting was significantly negatively associated with vegetable consumption (rho=-0.174, p<0.001) (boys and girls), and positively associated with consumption of fast food (rho=0.096, p<0.01) (girls) and soft drink (rho=0.114, p<0.001) particularly for boys. Authoritarian parenting was not associated with BMI Z. This body of work has presented evidence that home environments play an important role in shaping Pacific children’s food consumption patterns especially in light of the need to address rapid growth and obesity. Analyses point to the continued influence of macro environmental socioeconomic pressures mediated through Pacific family homes such as in the positive relationship between household size and consumption of energy-dense foods, bread and soft drink; the two foods that were significantly related to BMI Z (at 9, 11 and 14 y). These observations were consistent and reinforced by the associations observed between indicators of maternal deprivation and all selected food habits at age 9 y. However, positive indications may be gleaned from characteristics in parenting styles that maintain high levels of control and responsiveness, moderating children’s food consumption and growth. As such, authoritative parenting practices were seen to have a positive effect on good eating habits and on cross-sectional and, importantly, longitudinal BMI Z among children. In order to counter poor nutrition, rapid growth and increased body size, a variety of macro- and micro-environmental measures must be addressed. At the macro level, policies must address increasing levels of poverty and the undersupply of housing in New Zealand, which are key environmental determinants of health. Improved social services to support families experiencing socioeconomic deprivation is recommended to improve food security particularly for children and pregnant mothers. In community settings, food retail environments that support heathier choices could also be a helpful strategy for improving child nutrition. At the micro-level, benefits may be gained in health and nutrition literacy for parents and support strategies to improve food environments in the home. Improved nutrition for Pacific children will have positive flow-on effects in other areas of health apart from body size, improvement of overall quality of life, a more productive workforce, improved health of the next generation and reduction in the cost of non-communicable diseases on the national health budget.