Background:
Childhood poverty is associated with poorer food consumption patterns but longitudinal data on this association is limited. To assess if the relationship between food consumption and poverty differs depending on the child’s age and pattern of poverty, we analyzed the relationship between consumption of selected foods and poverty trajectories at various ages in a birth cohort.
Methods:
The 1998-2010 "Quebec Longitudinal Study of Child Development" (n=2,120) cohort was used for these analyses. Household income was measured annually with poverty defined as income below the low-income thresholds established by Statistics Canada adjusted for household size and geographic region. Frequency of children’s consumption of dairy (milk, cheese, yogurt), fruits, and vegetables were reported by parents using a food frequency questionnaire. Analyses were conducted on the 739 children with food consumption data. Trajectories of poverty at 6, 8, 10, and 12 years were characterized with latent class group analysis using maximum likelihood in a semiparametric mixture model. Multivariable logistic regression predicted the likelihood of having less than 2 servings a day of dairy, fruits and vegetables based on poverty trajectories after adjusting for age and sex.
Results:
The poverty trajectories were stable and fell into 1 lower exposure category (consistently low exposure (73%, n=537)) and 3 higher exposure categories (increasing: 8%, n=61; decreasing: 10%, n=73; or consistently high exposure: 9%, n=68)). Compared to children experiencing low exposure to poverty, children with increasing or high exposure to poverty were less likely to have at least two servings of fruit a day at all ages, but the results were not significant. Compared to children experiencing low exposure to poverty, children with high exposure were 55% (CI: 0.2-0.8, p=0.001), 31% (CI: 0.4-1.2, p=0.23), 67% (CI: 0.2-0.6, p<.0001), and 49% (CI: 0.3-0.8, p=0.001) less likely to have at least two servings of dairy a day at 6, 8, 10, and 12 years, respectively. Compared to children with low exposure to poverty, children with high exposure were 43% (CI: 0.3-0.9, p=0.02), 46% (CI: 0.3-0.9, p=0.02), 55% (CI: 0.3-0.8, p=0.003), and 47% (CI: 0.3-0.9, p=0.02) less likely to have at least two servings of vegetables a day at 6, 8, 10, and 12 years, respectively. Children at all ages with decreasing or increasing exposure to poverty were less likely to have at least two servings of vegetables a day, but the results were not statistically significant.
Conclusion:
Experiencing high exposure to poverty has consistent effects on food consumption throughout childhood. In addition, compared to children with low exposure to poverty, children with increasing or decreasing exposure were less likely to have at least 2 servings of fruits and vegetables a day, suggesting any exposure to poverty may have detrimental effects on consumption of selected foods.
Evaluation and interpretation of latent class modelling strategies to characterise dietary trajectories across early life: a longitudinal study from the Southampton women's survey
