Lower prices for healthy foods and higher prices for less healthy foods could improve the health of American children.

That is the take-away from a study called “The Effect of Food and Beverage Prices on Children’s Weights,” authored by Minh Wendt and Jessica Todd, economists with the U.S. Department of Agriculture’s Economic Research Service.

The study examined food prices and their effect on children’s weights 1998 through 2006. The children were observed between kindergarten through eighth grade and researchers linked the weights of those children with the Quarterly At Home Food Price Database.

Similar to other research, Todd said that the study found small but statistically significant effects between higher prices for less healthy foods and lower body mass index levels for children. In addition, the study found that higher prices for healthy foods are associated with lower BMI levels for children.

“The main contribution is that we are able to differentiate between a more refined group of foods,” she said.

The study looked at different vegetable types and also included measures on a wider range of beverages.

Todd said the study doesn’t look at the affordability of fruits and vegetables, but rather addresses the effect of small price changes.

“Individuals and parents are going to respond to changes in prices at many different levels, not only the absolute price they have to pay in relation to their income but also in comparison to other options,” she said.

“Making fruits and vegetables less expensive may have a small effect on children’s weight, in the right way,” she said.

Likewise, increasing the price of less healthy foods may have just as large an effect as reducing the price of healthy foods, she said.

The study found a 10% drop in the price of dark green vegetables in the previous quarter was associated with a reduction of children’s’ body mass index by 0.28%. In contrast, a decrease in the price of sweet snack was linked to an increase in children’s’ body mass index of 0.27%.

The research discovered that prices for healthy foods such as low-fat milk and green vegetables have larger effects on higher BMI children than on children of average weight. In addition, the study found larger effects among children in lower-income households.