Shift-and-persist: a protective factor for elevated BMI among low-socioeconomic-status children.

OBJECTIVE Low socioeconomic status (SES) is associated with many adverse health outcomes, including childhood overweight and obesity. However, little is understood about why some children defy this trend by maintaining a healthy weight despite living in obesogenic environments. The objective of this study is to test the hypothesis that the psychological strategy of "shift-and-persist" protects low-SES children from overweight and obesity. Shift-and-persist involves dealing with stressors by reframing them more positively while at the same time persisting in optimistic thoughts about the future. DESIGN AND METHODS Middle school children (N = 1,523, ages 9-15) enrolled in a school-based obesity prevention trial completed health surveys and physical assessments. Multiple linear regression analysis was used to examine the role of SES, shift-and-persist strategies, and their interaction on BMI z-scores, while controlling for student race/ethnicity, gender, and reported diet and physical activity. RESULTS Among children reporting engaging in less frequent shift-and-persist strategies, lower SES was associated with significantly higher BMI z-scores (P < 0.05). However, among children reporting engaging in more frequent shift-and-persist strategies, there was no association of SES with BMI z-score (P = 0.16), suggesting that shift-and-persist strategies may be protective against the association between SES and BMI. CONCLUSIONS Interventions aimed at improving psychological resilience among children of low SES may provide a complementary approach to prevent childhood overweight and obesity among at-risk populations.