As children age, the quality of their snacks appears to decline, according to a recent study.

Researchers from Brown University and Tufts University set out to explore how eating frequency relates to energy intake and diet quality in a sample of low-income, urban schoolchildren in the Boston area. They expected that snacking would substantially contribute to kids' overall energy intake, and the new data confirm that. But they were surprised that the nutritional value of snacks and meals differed by age.

"Unexpectedly, in elementary school-age participants we found that overall eating frequency and snacks positively contributed to diet quality," researchers wrote in the study. "In adolescents, however, our results suggested that snacks detract from overall diet quality while each additional meal increased diet quality."

For the study, researchers asked 92 kids, aged 9 to 11, and 84 teens from four Boston-area schools to provide some basic demographic information. Then, on two separate occasions, the kids completed a 24-hour diet recall, in which they recounted what they ate during the previous day. The kids were provided with references to help them describe what and how much they consumed.

Using this information, researchers determined the number of meals and snacks reported by each child, along with their total energy intake and diet quality score, as measured by the Healthy Eating Index, 2005. In all their analyses, the researchers accounted for variables such as gender, ethnicity, eligibility for free and reduced-price lunches, maternal education, and levels of physical activity.

They found that among the cohort of school-age children, each snack raised their diet quality by 2.31 points, as measured on the Healthy Eating Index, 2005 developed by the U.S. Department of Agriculture. Among the 84 teens in the study, aged 12 to 15, each snack dragged the quality score down by 2.73 points whereas each meal increased the quality score by 5.40 points.

The findings suggest a clear decay in snacking quality as children age, but rather than despairing, parents, educators and other care providers can make use of the findings, Whitney Evans, first author of the study, said in a statement.

Researchers said parents could remedy this by emphasizing good snacking habits among younger kids, who may be relatively receptive to such messages, so that their potential decline may start from a better place. Another strategy is to recognize that adolescents may be inclined to make worse choices and take steps to prevent that.

"It's important to help adolescents understand the implications of snacking, Evans said."For example, snacks that could occur as mindless eating in front of the television may be the ones that increase their weight over time."

The findings were recently published in the journal Public Health Nutrition.