Challenges in Understanding the Relationship Between Socioeconomic Status and Obesity Risk
Despite the substantial variation in BMI that exists as a function of both SES and race/ethnicity, uncertainties remain as to whether these rates can be attributed solely to SES, because obesity disparities are not the same across ethnic groups and they do not emerge at comparable times during childhood (Parsons et al., 1999). There is no consensus about the reasons for these disparities, although recent research provides certain insights. Variation in obesity risk by race/ethnicity and SES appears to occur early in life. An assessment of 16,000 preschool children, ages 2 to 4 years, enrolled in the Head Start Program in New York City found that 27 percent were obese and 15 percent were at risk for obesity. An estimated one in four Head Start children in that sample were found to be obese by the age of 2 years, and one in three children were obese by the age of 4 years. Although obesity was identified as a problem among all Head Start children in New York City, Hispanic/Latino and African-American preschoolers are disproportionately affected (New York City Department of Health and Mental Hygiene, 2006). Moreover, socioeconomic deprivation in childhood has been found to be both a strong predictor of obesity in adulthood for African-American adult women (James et al., 2006a) and adult hypertension in adulthood for African-American men (James et al., 2006b).
Mexican-American children and youth living along the U.S.-Mexico border experience higher levels of economic disadvantages and special challenges in accessing foods that contribute to a healthful diet, regular physical activity, and health care services (Abarca and Ramachandran, 2005; Ruiz-Beltran and Kamau, 2001). Low-SES Mexican school-aged children living along the U.S. border in Tijuana, adjacent to San Diego County in California, have been found to be at increased risk of obesity and related chronic diseases, which may be related to less healthful food choices for children attending schools in low-SES neighborhoods (Villa-Caballero et al., 2006). In contrast, among Mexican children and adolescents, particularly those living in urban areas, obesity is increasing among higher SES groups (IOM, 2007).