Adolescent girls who followed a Dietary Approaches to Stop Hypertension (DASH)-style eating plan had lower body mass indexes (BMIs), sustained over a 10-year period, than those who did not follow this diet, a new epidemiologic.

Avoiding excessive weight gain during adolescence is a key way of preventing adult obesity and its attendant problems, say Dr Jonathan P B Berz (Boston University Medical Center, Boston, MA) and colleagues in their paper published in the June 2011 issue of the Archives of Pediatrics & Adolescent Medicine.



Although the DASH diet—which emphasizes increased intakes of low-fat dairy products, fish, chicken and lean meats, nuts, fruits, whole grains, vegetables, and legumes—is well-established as a healthy eating pattern for adults with hypertension and metabolic syndrome, it has been infrequently studied in children, they note.

"We found that higher adherence to a DASH-style diet resulted in a consistently lower BMI between the ages of nine and 19 years. Such an eating pattern may help prevent excess weight gain during adolescence," they observe.

In an accompanying editorial, Drs Robert C Klesges and Marion Hare (University of Tennessee Health Science Center, Memphis) say the study by Berz et al adds "to a growing body of literature that will eventually help us to understand and hopefully treat pediatric obesity. A logical next step . . . is to test the DASH diet in children along with other efficacious adult obesity interventions."

Higher DASH score=higher energy intake, but smallest gain in BMI

Berz and colleagues evaluated the effects of a DASH-style diet on BMI in a racially diverse sample of 2237 girls aged nine years who participated in the National Growth and Health Study from 1987 to 1988 and were followed up for 10 years. Data were gathered annually, and each participant was given a DASH food group score based on individual adherence to dietary requirements, rather than simply relying on food frequency questionnaires. This method has not been used often in studies of adolescents and so represents a particular strength of this research, say the authors.

The study was performed on an assessment-only basis: higher DASH scores were associated with higher total energy intake, as well as higher average intake from each food group.

Girls in the highest quintile of DASH scores had the smallest gains in BMI during the study and had the lowest BMIs at the end of follow-up. Conversely, at age 19 years, girls in the lowest DASH score quintile had an average BMI that was greater than the threshold for overweight as defined by the 85th percentile for age.

"In particular, higher consumption of fruits, whole grains, and low-fat dairy products led to less weight gain," say Berz et al. Those who ate two or more servings of fruit per day had the smallest gains in BMI during the study years and the lowest BMI at the end of follow-up. Results were similar for whole-grain and low-fat dairy consumption—those who consumed the most of these food groups had lower BMI scores over time and a lower BMI at the end of follow-up.

The study included a socioeconomically and geographical diverse sample of girls, the authors note, adding that it included more than 50% black girls, "a population particularly beset by the obesity epidemic."

Small changes can have a large impact among children

In their editorial, Klesges and Hare say the new findings are "significant and timely," although they also point out that the figures are somewhat "dated" because the study began in the 1980s.

"The DASH diet is flexible and should meet the food preferences of most children," they observe, although they stress that for pediatric and adolescent patients, "interventions need to be simplified."

They recommend a "4 As" approach to prevent excess weight gain in adolescence: assess, advise, assist, and arrange for follow-up. "Often the goal of pediatric obesity programs is not to reduce weight but to maintain current weight so that as the children grow, BMI will decrease; therefore, small changes can have a large impact," they observe.

Simple advice includes recommending low-fat dietary alternatives and eliminating or reducing consumption of sweetened beverages, as well as suggestions to consult family websites that promote healthy eating and fun activities.

Finally, a follow-up visit to determine progress and adjust recommendations is "crucial. If your patients and their parents do not think that you believe weight control is an important issue, they will not see it as one either."

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