Household Income, Cortisol, and Obesity During Early Childhood: A Prospective Longitudinal Study.

OBJECTIVE: To prospectively evaluate the relationship between household income, children's cortisol, and body mass index (BMI) trajectories over a 3-year period in early childhood. STUDY DESIGN: Household income, child hair cortisol levels, and BMI were measured at baseline, 12-, 24-, and 36-month follow-up visits in the Now Everybody Together for Amazing and Healthful Kids (NET-Works) Study (n = 534, children ages 2-4 years, and household income <$65 000/year at baseline). Relationships were examined between very low household income (<$25 000/year) at baseline, income status over time (remained <$25 000/year or had increasing income), cortisol accumulation from hair samples, and BMI percent of the 95th percentile (BMIp95) trajectories using adjusted linear growth curve modeling. Households with baseline income between $25 000 and $65 000/year were the reference group for all analyses. RESULTS: Children from very low-income households at baseline had annual changes in BMIp95 that were higher (P < .001) than children from reference group households (0.40 vs -0.62 percentage units/year). Annual increases in BMIp95 were also greater among children from households that remained very low income (P < .01, .34 percentage units/year) and among those with increasing income (P = .01, .51 percentage units/year) compared with the reference group (-0.61 percentage units/year). Children from households that remained very low income had higher hair cortisol accumulations (0.22 pg/mg, P = .02) than reference group children, whereas hair cortisol concentrations of children from households with increasing income (0.03 pg/mg) did not differ significantly from the reference group. Cortisol was not related to BMIp95. CONCLUSIONS: The economic circumstances of families may impact children's BMI trajectories and their developing stress systems, but these processes may be independent of one another.

A Bidirectional Analysis of Feeding Practices and Eating Behaviors in Parent/Child Dyads from Low-Income and Minority Households.

OBJECTIVE: To prospectively examine the bidirectional relationship between parental feeding practices (eg, instrumental feeding, encouragement to eat) and child eating behaviors (eg, food responsiveness, emotional eating) in low-income, ethnically diverse preschool children over a 3-year period. STUDY DESIGN: Parent/child (age 2-4 years at baseline) pairs (n = 222 non-Hispanics; n = 312 Hispanics) participated in NET-Works (Now Everybody Together for Amazing and Healthful Kids), a randomized controlled trial carried out in community and in-home settings in urban areas of Minnesota. Data were collected at baseline and 12, 24, and 36 months. The present study is a secondary data analysis using cross-lagged models to identify bidirectional associations between parental feeding practices and child eating behaviors. RESULTS: Three models showed significant cross-lagged effects (P < .05): model 1, parental instrumental feeding influencing later child food responsiveness; model 2, parental emotional feeding influencing later child food responsiveness; and model 3, parental emotional feeding influencing later child eating satiety. Model 1 showed significant bidirectional temporal paths, whereas models 2 and 3 showed significant unidirectional temporal paths from parental feeding practices to child eating behaviors. CONCLUSIONS: Parental instrumental and emotional feeding practices prospectively influence child food responsiveness and satiety. This study demonstrates causal temporality between parental feeding practices and child eating behaviors. Heath care providers may want to use findings regarding parent feeding practices as part of their anticipatory guidance during well-child visits with parents of preschoolers.