Better Diet Quality in the Healthy Hunger-Free Kids Act and WIC Package Reduced Childhood Obesity

The HHFKA was passed by Congress in 2010, and its implementation was required in schools by 2012. In the Act, Congress set age-appropriate caloric ranges, required that at least 51% of grains be whole grains, required students to take at least one-half cup serving of fruits or vegetables with every school breakfast or lunch, and required that schools offer 1 cup of flavored or unflavored fat-free milk or 1% milk. Despite concerns, the changes were not associated with an increase in plate waste.¹  In several studies, researchers have confirmed an increase in the quality of school meals and in improved consumption. For example, dietary quality was assessed before and after implementation of the new HHFKA standards by using the Healthy Eating Index 2010 (HEI 2010) and food consumption data from the nationally representative NHANES.²  The HEI 2010 score reflected the degree to which dietary intake was consistent with the 2010 Dietary Guidelines for Americans. The HEI 2010 scores among students aged 5 to 18 years were stratified by low-income, low-middle–income, and middle-high–income students and compared to those among non–school lunch participants in the same income categories. The HEI 2010 scores increased from 42.7 to 54.6 among school lunch participants compared to a decrease from 34.8 to 34.1 among nonparticipants. The differences in comparison with non–school lunch participants were 12.6, 12.4, and 8.1 in low-, low-middle–, and middle-high–income participants, respectively. Furthermore, these changes appeared to carry over to differences in dietary quality for the entire day among school lunch participants compared with nonparticipants.² 

The impact of the standards instituted by the HHFKA on the prevalence of obesity was recently assessed by using data from the National Survey of Children’s Health.³  Obesity prevalence trends were assessed in youth aged 10 to 17 years in 2003, 2007, and 2011–2012 before implementation of the HHFKA standards and in 2016, 2017, and 2018 after implementation. To control for possible changes in sociodemographic characteristics over time, the data were adjusted for race and ethnicity, household poverty index, age, and biological sex. Preexisting state school meal policies and foods served outside the school meal program were also controlled. Because youth in poverty are more likely to consume school meals, and therefore more likely to be affected by the changes instituted by the HHFKA, poverty status was included in the pre-HHFKA and post-HHFKA trends. In the overall sample, there was no significant trend in the odds of having obesity for the entire group before or after implementation of the HHFK standards. However, the prevalence of obesity for youth in poverty, which had been increasing significantly each year before institution of the HHFKA, began decreasing each year thereafter. By 2018, the declines amounted to a 47% decrease in the predicted probability of obesity.³ 

In 2009, the US Department of Agriculture began to institute changes in the WIC package that were recommended on the basis of a consensus study conducted by the Institute of Medicine. These changes included a reduction in the quantity of milk, from 24 quarts of whole milk to 16 quarts of low-fat (1%) milk per month, and a reduction in the amount of vitamin C–rich juice, from 228 to 128 fl oz per month. At the same time, the food package included more fruits, vegetables, and whole grains. The changes to the WIC package were implemented in 2010. In a systematic review that included 9 studies of dietary intake before and after the implementation of the new WIC package, researchers found an increase in the consumption of whole-grain products and fruits and vegetables and a decrease in juice and whole-milk consumption.⁴  Increased intake of whole grains and decreased intake of juice were the most significant reported changes.

Repeated cross-sectional studies of the prevalence of obesity in children aged 2 to 4 years enrolled in WIC have been used in several reports to examine the impact of the changes in the WIC food package on the prevalence of obesity. The prevalence of obesity among WIC participants aged 2 to 4 years rose steadily from 2000 onward, reaching a peak prevalence of 15.9% in 2010 but, coincident with the changes in the WIC food package, subsequently decreased to 14.5% by 2014 and 13.9% by 2016.⁵  When adjusted for the interaction of survey cycle with age, sex, and race and ethnicity, the adjusted prevalence difference between 2010 and 2016 was a decrease of 1.9%. In contrast to other studies, the adjusted prevalence differences in obesity were greater in non-Hispanic Black (0.5%), Hispanic (2.1%), American Indian or Alaskan native (1.7%), and Asian or Pacific Islander children (1.7%) than in non-Hispanic white children, indicating that the intervention did not increase disparities in the prevalence of obesity. Severe obesity in children aged 2 to 4 years in all subgroups declined over the same time period.⁶  Because WIC participation among children aged 3 and 4 years in 2017 was between 40% and 25%, respectively, these changes may have contributed to the declines in the prevalence of obesity among children aged 2 to 5 years observed in the NHANES between 2009–2010 and 2013–2014.

The association of changes in dietary intake with changes in obesity are consistent with a longitudinal study of children aged 7 to 13 years enrolled in the Avon Longitudinal Study of Parents and Children in the United Kingdom.⁷  Foods associated with weight gain in 3-year periods included a number of high-fat foods, processed meats, and sugary drinks, whereas foods associated with weight loss included whole grains and high-fiber cereals. In a 12- to 20-year follow-up of the association of weight changes with changes in food intakes in 4-year periods among participants in the Nurses’ Health Study, Nurses’ Health Study 2, and the Health Professionals Follow-up Study, researchers also reported weight losses over time in association with increased intakes of fruits, vegetables, and whole grains.

These observations illustrate the positive impact on obesity of population-wide changes in federal regulatory and legislative food policies that improved the dietary intake of children and adolescents. It is of considerable importance that these policies and the changes associated with them focused on food quality rather than caloric restriction. Furthermore, the improvements in food quality were associated with significant decreases in the prevalence of obesity among our most vulnerable youth.

The coronavirus disease 2019 pandemic threatens the gains in reducing obesity achieved by the changes in the HHFKA and the WIC package. Although the literature is inconsistent, researchers in some studies indicate that food insecurity is associated with obesity in adults and children. The rapid increase in food insecurity caused by unemployment and the rising costs of food and reductions in physical activity associated with the lockdown may both increase obesity. Increasing the enrollment of WIC-eligible children could reduce both food insecurity and obesity. It is therefore essential that pediatricians ask families about the adequacy of their food supply and, if appropriate, provide them with the information necessary to enroll their children in WIC. School closures have shifted the provision of meals consumed in school to meals that are being distributed by schools. However, meeting the standards of the HHFKA may be challenging when these meals do not require refrigeration or cooking. Assuring that the quality of these meals continues to meet the standards of the HHFKA must remain a priority to sustain the impact of the HHFKA standards on obesity.

The high prevalence of obesity in the US population, the increased prevalence of obesity among minority populations, and the paucity of effective population-wide strategies emphasize that the reductions in obesity achieved by these programs must be sustained, expanded when feasible, and defended against the efforts to weaken, revoke, or delay their implementation.

HEI 2010

Healthy Eating Index 2010

HHFKA

Healthy, Hunger-Free Kids Act

WIC

Special Supplemental Nutrition Program for Women, Infants, and Children