A longitudinal study has found that while higher income children eat worse at school, low-income kids eat healthier than at home. While the political controversy rages over federal efforts to manage local school lunch programs, more data on who has actually been helped by the program over time is needed. 

The results in Preventive Medicine showed that fruit and vegetable intake was higher among low income adolescents on days when they consumed meals at school. The opposite was true for high income adolescents who consumed fewer fruits and vegetables when school was in session, compared to summer months. While in school, all students consumed fruits and vegetables with similar frequency regardless of income level.

The results were derived surveying 1,885 NH and VT middle school students and their parents by phone. They say their longitudinal study design was a type of "natural experiment" because they randomly allocated participants to be surveyed at different times of the year. This created comparable groups of adolescents who were, or were not, being exposed to school food by virtue of when they were surveyed. This facilitated comparison of fruit and vegetable consumption during the school months and over the summer. The survey asked the adolescents to recall fruit and vegetable consumption in the previous seven days.

Previous studies have claimed that kids from low income households eat fruits and vegetables less often than their high income peers and that has been the impetus for federal programs to change school lunch programs. By comparing consumption in and out of school by income group, the results may instead show that programs geared toward reducing obesity are having no effect at all on higher income students while they may be penalizing lower income ones. 

"Schools clearly have a role in providing healthy foods to children. Our data suggest that the most vulnerable students are benefitting the most from school food," says Madeline Dalton, PhD of Dartmouth Hitchcock's Norris Cotton Cancer Center and The Hood Center for Children and Families.