The growing racial disparity in obesity has reached a critical juncture, particularly among black and white females. Obesity is now being perpetuated across generations While there is uncertainty about how best to prevent obesity and the related racial disparities, converging lines of evidence support the influence of stress on obesity. We hypothesize that income and race are associated with higher levels of both objective and perceived stress, which in turn are associated with higher rates of nonhomeostatic eating, a behavior posited to result in an increased rate of obesity. Finally, we propose that stress has a direct effect on the level of obesity in the offspring. [More Details…] We propose to model these relationships longitudinally using the National Growth and Healthy Study (NGHS) that was conducted in three US sites enrolling equal numbers of black and white girls and that contains extensive data on several measures of life stress, nonhomeostatic eating and household demographic and socioeconomic indicators for black and white girls initially sampled at age 10 and interviewed annually until age 20. We will extend these data, adding a new wave of data collection to the Richmond, CA cohort of the NGHS. We will interview participants regarding their current weight status, stress factors, household food insecurity, and non-homeostatic eating behaviors such as emotional eating and food dependence. Building on the rich source of longitudinal data that NGHS provides, we will model the relationships between these factors and weight status from early childhood to adulthood among these girls who are now 30 years old. We will also collect data on the children of the NGHS participant in order to examine the effects of stress and obesity on obesity in the next generation. The study aims to test the hypotheses that: 1) income and race are associated with higher levels of stress which in turn is associated with higher rates of non-homeostatic eating in women; 2) non-homeostatic eating in turn results in an increased rate of obesity, exacerbated by food insecurity and restrained eating; and 3) maternal stress has a direct effect on the level of obesity in offspring. Our preliminary data suggests that stress and emotional eating both lead to weight gain ten years later in the NGHS cohort. We hope to identify specific predictors of weight gain trajectories from childhood to adulthood. These constructs have the potential to lead to promising interventions coupled with traditional diet and physical activity components that will help girls and women throughout the life course.
PI: Barbara Laraia
Co-Investigators: Elissa Epel, David Rehkopf
Funding: Robert Wood Johnson
Specific Aims:
Specific Aim 1: Identify whether stress and nonhomeostatic eating in childhood are associated with weight status at age 19 among girls in the full NGHS cohort.
Specific Aim 2: Determine whether life stress and nonhomeostatic eating predict change in weight status and abdominal fat distribution among the NGHS follow-up cohort through age 30.
Specific Aim 3: Determine whether maternal early life and adult stress and nonhomeostatic eating predicts obesity in the children of the NGHS cohort.