Food and Nutrition Assistance Programs and Obesity: 1976-2002
by
Michele Ver Ploeg,
Lisa Mancino, and
Biing-Hwan LinEconomic Research Report No. (ERR-48) 42 pp, September 2007
The marked rise of obesity in the United States has many
wondering what factors have contributed to this trend.
Technological changes that have affected the price of food and the
time costs of preparing it, increased variety and frequency of food
consumption, and increasingly sedentary lifestyles have been named
as suspects. Environmental factors, such as the per capita number
of restaurants, and unintended consequences of policies such as
State cigarette taxes, have also been blamed for increases in
obesity.
What Is the Issue?
High rates of overweight and obesity among low-income
populations in the United States have raised questions about
whether Federal food and nutrition assistance programs contribute
to the problem. Critics contend that the Food Stamp Program (FSP),
the Special Supplemental Nutrition Program for Women, Infants, and
Children (WIC), and National School Lunch and School Breakfast
Programs, all designed to reduce poor nutrition, may, ironically,
encourage participants to overeat and gain weight. To examine this
possibility, the study investigated the extent to which overweight
and obesity have increased over time for food and nutrition
assistance recipients (focusing on FSP and WIC), and the degree to
which increases may simply mirror national trends in overweight and
obesity. For this analysis, the study compared food and nutrition
assistance program participants to low-income individuals who were
not participating in the programs and to individuals with higher
incomes.
What Did the Study Find?
In contrast to previous years, the most recent data from the
National Health and Nutrition Examination Surveys (NHANES) show
almost no relationship between food stamp participation and weight
status. The most striking shift over time is observed among
non-Hispanic White women. Data from 1976-1980 showed that food
stamp participants had a greater body mass index (BMI) and were
more likely to be overweight and obese than nonparticipants.
However, data from 1999-2002 show no differences between food stamp
participants and income-eligible nonparticipants. Further, BMI and
the likelihood of overweight and obesity were similar for both
moderate-income non-Hispanic White women and food stamp
participants. For other age, sex, and race/ethnicity groups, an
inconsistent relationship between food stamp participation and
weight measures was found.
More detailed results of the comparisons within demographic
groups were:
Women-Data from 1976-80 and 1988-94 showed a
strong positive association between Food Stamp Program
participation and each of the three weight outcomes in adult
non-Hispanic White women. Data from 1999-2002, however, showed no
correlation between any of the three weight outcomes and food stamp
participation status. Further, 1999-2002 data for non-Hispanic
White women showed no differences in all three weight outcomes
between food stamp participants and moderate income women and
showed that only higher income women had lower BMI and were less
likely to be obese than food stamp participants. For non-Hispanic
Black women, data from 1976-80 and 1988-1994 did not show a
consistent relationship between food stamp participation and body
weight-only non-Hispanic Black women with the highest incomes had
lower BMI and were less likely to be overweight or obese than food
stamp participants. In 1999-2002, even this difference did not
exist. Results for Mexican-American women reflect those of
non-Hispanic White women.
Men-Data from the earlier years show the
association between program participation, income, and weight among
men was nearly the opposite of that for women. Male food stamp
participants were less likely to be overweight than eligible
nonparticipants and moderate and higher income men. But in
1999-2002, for non-Hispanic Black and White men, no weight gap was
observed between food stamp participants and nonparticipants.
Children-The largest proportion of recipients
in both the Food Stamp and WIC programs are children, who have
recently comprised about 50 percent of participants in both
programs. For the analysis, the study authors divided them into two
age groups, as follows:
School-Age Children (ages
5-17)-Analysis for this group showed no systematic
associations between receipt of food stamps and weight. Differences
in weight between participants and nonparticipants existed only in
some years and for some racial and ethnic groups. Further, the
direction of the estimated coefficient signs varied over time and
by subgroup. The results also varied according to whether a
household or individual measure of food stamp participation was
used, particularly for Mexican-American children.
Young Children (ages 2-4)-No
differences in weight outcomes were found between WIC participants
and eligible nonparticipants. However, the more recent data showed
some differences between WIC participants and higher income boys,
with higher income boys having significantly lower BMI and risk of
overweight.
How Was the Study Conducted?
To examine the relationship between body weight and food and
nutrition program participation over time, the authors used
multivariate analysis with multiple periods of cross-sectional data
from the National Health and Nutrition Examination Surveys (NHANES)
for 1976-80, 1988-94, and 1999-2002. For adults, the authors
examined BMI, probability of overweight, and probability of
obesity, and for children, BMI, probability of at-risk for
overweight, and probability of overweight. For adults and
school-age children, the association between Food Stamp Program
participation and weight was investigated by comparing participants
with income-eligible and moderate and higher income
nonparticipants. For young children (ages 2-4), similar comparisons
were made for WIC participation and weight. Separate models by sex
and race/ethnicity (non-Hispanic White, non-Hispanic Black, and
Mexican American) were examined.