Principal Investigator: Linda Van Horn, PhD, RD
Co-Investigators: Katherine Christoffel, MD, MPH and Kiang, Liu, PhD

In 1987, the Dietary Intervention Study in Children (DISC), a ten-year study funded by National Institutes of Health, was launched. This randomized, multi-center clinical trial examined the effect of a diet low in saturated fat and cholesterol on the growth, development and lipid levels among more than 600 hyperlipidemic children age 8-10 (at the time of study enrollment). These participants' baseline LDL-C levels were between the 80th-95th percentiles for age. No cholesterol-lowering medications were used during the course of the study.

Study Design

Approximately 300 children randomized into the control group followed a typical American diet high in saturated fat and cholesterol. Another 300 participants were assigned to the dietary intervention group.

Dietary Intervention

The nutrition intervention of the study focused on tailoring the DISC low fat dietary prescription to the participant's food preferences, lifestyle habits and family dynamics to promote optimal adherence. Participants and their families were initially engaged in intensive intervention by attending weekly nutrition sessions during the first year of the program. Maintenance classes were offered during the remaining years of the study to help reinforce the desired DISC nutrition principles and eating behavior concepts.

Considering the young age of the DISC population, dietitians taught age-appropriate nutrition concepts to these children during each DISC session. The parents also attended separate classes that focused on healthy eating principles. Basic nutrition concepts, product label reading and low fat cooking techniques were addressed in both the child and parent DISC sessions.

The DISC Go! Guide was the primary resource for helping both DISC children and their parents make heart-healthy food choices on a daily basis. The DISC Wheel was a simple visual tool that illustrated the DISC Go! Guide concepts. The DISC Wheel categorized foods by their saturated fat and cholesterol content into eight different food groups. The "GO" foods (low in saturated fat and cholesterol) were the "target" foods arranged around the bulls-eye of the circle whereas "WHOA" items (high in saturated fat and cholesterol) were arranged in the outer circle of the DISC Wheel.

During adolescence, the course of DISC nutrition intervention evolved from a group educational format to intensive individual counseling. The inherent behavioral changes associated with adolescence inspired DISC nutritionists to develop a customized intervention approach called motivational interviewing. This method was adapted from a motivational counseling concept pioneered by Miller and Rollnick that included assessment of a patient's stages of behavioral change.

Data Collection

Clinical evaluation included biochemical, clinical, anthropometric, nutrition, physical activity and psychosocial information on the DISC participants as well as their families. Diet assessment entailed (1) self-administered Diet Acceptability Questionnaire (i.e. probed participant's attitudes about the DISC diet) and (2) three random 24-diet recalls at scheduled clinic visits throughout the study.

Sources:

Obarzanek E., Kimm S Y S, Barton B A, Van Horn L, Kwiterovich Jr. P O, Simons-Morton D G, Hunsberger S A, Lasser N L, Robson A M, Franklin Jr. F A, Lauer R M, Stevens V J, Friedman L A, Dorgan J F, Greenlick M R. Long-Term safety and efficacy of a cholesterol-lowering diet in children: seven-year results of the Dietary Intervention Study in Children (DISC). JAMA. 1999; Vol. 100; 1:51-59.

Berg-Smith SM, Stevens VJ, Brown, KM, Van Horn L, Gernhofer N, Peters E., Greenber R, Snetselaar L., Ahrens L., & Smith K.. A brief motivational intervention to improve dietary adherence in adolescents. Health Education Research 1999:14:399-410.

Van Horn L. Primary prevention of cardiovascular disease starts in childhood. JADA. 2000; Vol. 100; 1:41-42.