Prevalence and maternal determinants of early and late introduction of complementary foods: results from the Growing Up in New Zealand cohort study

A nationally generalisable cohort (n 5770) was used to determine the prevalence of non-timely (early/late) introduction of complementary food and core food groups and associations with maternal sociodemographic and health behaviours in New Zealand (NZ). Variables describing maternal characteristics and infant food introduction were sourced, respectively, from interviews completed antenatally and during late infancy. The NZ Infant Feeding Guidelines were used to define early (<= 4 months) and late (>= 7 months) introduction. Associations were examined using multivariable multinomial regression, presented as adjusted relative risk ratios and 95 % confidence intervals (RRR; 95% CI). Complementary food introduction was early for 40 center dot 2 % and late for 3 center dot 2 %. The prevalence of early food group introduction were fruit/vegetables (23 center dot 8 %), breads/cereals (36 center dot 3 %), iron-rich foods (34 center dot 1 %) and of late were meat/meat alternatives (45 center dot 9 %), dairy products (46 center dot 2 %) and fruits/vegetables (9 center dot 9 %). Compared with infants with timely food introduction, risk of early food introduction was increased for infants: breastfed < 6months (2 center dot 52; 2 center dot 19-2 center dot 90), whose mothers were < 30 years old (1 center dot 69; 1 center dot 46-1 center dot 94), had a diploma/trade certificate v. tertiary education (1 center dot 39; 1 center dot 1-1 center dot 70), of Maori v. European ethnicity (1 center dot 40; 1 center dot 12-1 center dot 75) or smoked during pregnancy (1 center dot 88; 1 center dot 44-2 center dot 46). Risk of late food introduction decreased for infants breastfed < 6 months (0 center dot 47; 0.27-0 center dot 80) and increased for infants whose mothers had secondary v. tertiary education (2 center dot 04; 1 center dot 16-3 center dot 60) were of Asian v. European ethnicity (2 center dot 22; 1 center dot 35, 3 center dot 63) or did not attend childbirth preparation classes (2 center dot 23; 1 center dot 24-4 center dot 01). Non-timely food introduction, specifically early food introduction, is prevalent in NZ. Interventions to improve food introduction timeliness should be ethnic-specific and support longer breast-feeding.

Automated summary

This study used a nationally generalisable cohort in New Zealand to examine the prevalence of non-timely introduction of complementary food and core food groups and its association with maternal sociodemographic and health behaviors. The results showed that early introduction of complementary food was common, while late introduction was less common. Factors such as breastfeeding duration, maternal age, education level, ethnicity, smoking during pregnancy, and attendance of childbirth preparation classes were associated with the timing of food introduction.