THE DIETARY INTERVENTION STUDY IN CHILDREN (DISC) - DIETARY ASSESSMENT METHODS FOR 8-YEAR-OLDS TO 10-YEAR-OLDS

Objectives The dietary assessment methods used in the Dietary Interven tion Study in Children (DISC) are described and the rationale, validit y, and/or general usefulness of each are discussed. Design DISC is the first multicenter, randomized, clinical trial to study the feasibilit y and long-term efficacy, safety, and acceptability of a fat-modified diet in 8- to 10-year-old prepubescent children with moderately elevat ed plasma low-density lipoprotein cholesterol (LDLC) levels. Final dat a collection for the original study (DISC T) occurred December 1, 1993 ; continued intervention and follow-up (DISC) will extend beyond 1997. Setting Six clinical centers across the country participate in DISC. Subjects Preadolescent boys and girls with fasting LDLC levels between the 80th and 98th age-specific and sex-specific percentiles establish ed by the Lipid Research Clinics were eligible for the study. The feas ibility phase included 140 children who were then enveloped into the f ull-scale trial. Baseline dietary data for 652 randomized children in the full-scale trial and 6-month results for the feasibility cohort ar e reported. Interventions Dietary assessment involved several elements : (a) determining eligibility based on consumption of more than 30% of energy from total fat., Co) monitoring adherence to and adequacy of t he intervention diet, (c) evaluating acceptability of the diet in the intervention group, and (d) determining appropriate foods for the inte rvention diet. Methods are described for each purpose. Main outcome me asures LDL-C differences between the two groups and differences in tot al and saturated fat intakes as calculated from three 24-hour recalls were the primary outcome measures. Six-month dietary differences in th e feasibility group are reported. Statistical methods Baseline group m eans and 6-month differences in dietary intake are reported for the fu ll-scale trial and feasibility study, respectively. Results Baseline m ean intake from three dietary recalls for the intervention (n=328) and control (n=324) groups, respectively, were as follows: energy = 1,759 kcal and 1,728 kcal; total energy from fat = 33.3% and 34.0%; total e nergy from saturated fat = 12.5%, and 12.7%; and total dietary cholest erol = 209 mg and 195 mg. After 6 months of intervention, percentage o f energy from total fat and saturated fat was reduced by 5.1% (P=.OO4) and 2.9% (P<.001), respectively, in this feasibility subset (n=73) of the intervention group. Essentially no change in these parameters occ urred in the control group (n=67), which demonstrates a measurable dif ference in reporting between groups. Applications/conclusions Results illustrate the feasibility of implementing a variety of dietary assess ment methods among preadolescent children without relying primarily on parental reports.