of Washington, who moderated the session on socioeconomic disparities, food security, and obesity. Measures of socioeconomic status have many shortcomings, for example, they typically are based on “snapshot” measures of current income or education. Such measures of income do not measure accumulated assets and wealth, and such measures of education can have little bearing on the current economic status of a person who is 50 and unemployed. A person’s employment status may be measured at one point in time, but that job could be lost the next day, noted Drewnowski. Furthermore, SES measures typically do not reflect economic insecurity, which is a measure of desperate need.
New and different measures to better understand economic security are important in understanding the relationship between food insecurity and obesity, said Drewnowski. Should such factors as assets, wealth, property values, neighborhood in which a person lives, or whom a person knows be included? What currently unobserved factors are important?
One question is whether socioeconomic status should be measured along a continuous gradient. Some studies have made income-based dichotomous distinctions between the poor and non-poor. At $19,000 a year, a person is poor. At $21,000 a year, that person is almost middle class, said Drewnowski. Yet SES is a complex construct that may affect health outcomes through diverse mechanisms and at different points in the life course. New ways to measure social disparities may provide new insights on the distribution of food insecurity and obesity among children and adults.
Gopal K. Singh, senior epidemiologist with the Maternal and Child Health Bureau, Health Resources and Services Administration, U.S. Department of Health and Human Services, described trends in obesity and overweight among children, adolescents, and adults and the extent to which socioeconomic disparities in obesity vary across the life course. He used data from three different nationally representative surveys: the National Health and Nutrition Examination Survey (NHANES), the National Health Interview Survey (NHIS), and the National Survey of Children’s Health (NSCH). The NHANES has been conducted periodically in the United States since the mid-1970s and since 1999 has been a continuous annual health examination survey with a sample size of about 10,000 children and adults for every 2-year cycle. The NHIS has been conducted continuously since 1957 and has a sample size of about 100,000 children and adults. The NSCH is the largest child health survey in the United States and is conducted every 4 years, with the next survey scheduled for 2011. It has a sample size of about 100,000 children less than 18 years of age. Body mass index (BMI) in NHANES is based on measured height and weight data,