A new study from the CHOICES Project at the Harvard T. H. Chan School of Public Health analyzed how trends in obesity among children participating in WIC changed after food package changes were enacted in 2009.
The aim of this study was to evaluate if the changes made to the foods that could be purchased through the U.S. Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) in 2009 had an impact on childhood obesity.
In 2009, the lists of foods that could be purchased with WIC vouchers (known as the WIC food packages), which includes basic food categories, were updated to better align with the Dietary Guidelines for Americans. The new package, still in use today, provided extra cash allowances for fruits and vegetables, cut the previous juice allowance in half, required low-fat or skim milk for 2-4 year olds, reduces cheese, and required whole-grain instead of refined-grain products (among other changes).
Earlier studies showed that this shift had resulted in significant changes in WIC participants’ diets and in lowering the amount of calories they consumed. The Centers for Disease Control showed that there had been some declines in childhood obesity prevalence among WIC participants in recent years.1 However, there had not yet been a direct test of whether the WIC package change may have catalyzed a turn-around in childhood obesity rates among WIC participants.
Using state-specific obesity prevalence data for 2-4 year olds participating in WIC from 2000 to 2014, the researchers estimated the annual trend in obesity prevalence across states, and then tested whether that trend significantly changed after the WIC package revision in 2009, adjusting for changes in demographics.
The key findings from the study include:
- Before the 2009 WIC food package change, the prevalence of obesity across states among 2-4 year olds participating in WIC was growing 0.23 percentage points annually.
- After 2009, this alarming trend switched direction. Instead, the prevalence of obesity across states among 2-4 year olds participating in WIC started decreasing by 0.34 percentage points annually.
These results suggest that the 2009 WIC food package change likely helped to reverse the rapid increase in obesity prevalence among WIC participants observed before the food package change, helping set the millions of young children who benefit from WIC on a path toward a healthier weight.
Daepp MIG, Gortmaker SL, Wang YC, Long MW, Kenney EL. WIC Food Package Changes: Trends in Childhood Obesity Prevalence. Pediatrics. 2019;143(5):e20182841. Address correspondence to Erica Kenney, ScD, MPH at ekenney@hsph.harvard.edu
References
- Pan L, Freedman DS, Sharma AJ, Castellanos-Brown K, Park S, Smith RB, Blanck HM. Trends in Obesity Among Participants Aged 2-4 Years in the Special Supplemental Nutrition Program for Women, Infants, and Children – United States, 2000-2014. MMWR Morb Mortal Wkly Rep. 2016 Nov 18;65(45):1256-1260. doi: 10.15585/mmwr.mm6545a2