Objective: To compare the effect of the addition of medical nutrition therapy administered by a registered dietitian with the usual physician counseling on nutrition knowledge, attitudes regarding dietary change, body mass index, dietary intake, and lipid and lipoprotein concentrations during initial management of persons at risk for cardiovascular disease.
Design: A 3-month prospective, randomized trial of subjects stratified by sex and assigned to one of four nested treatment groups, which were subsequently collapsed into two groups.
Subjects: Fifty-two men and 52 women classified at risk for cardiovascular disease.
Intervention: Two groups of subjects received dietary counseling from a physician or nurse; in one group the Grocery Shopping Guide was used. Two other groups received medical nutrition therapy from a registered dietitian (one or three visits) in addition to the instruction from a physician or nurse and the information provided by the Grocery Shopping Guide.
Statistical analyses: Analyses of covariance were performed to determine differences between the groups. Paired t tests were performed to study changes within the groups.
Results: The group receiving medical nutrition therapy from a registered dietitian gained statistically significantly more nutrition knowledge; had significantly greater perceptions of the benefits and efficacy of following a cholesterol-lowering diet; consumed a significantly lower percentage of fat, higher percentage of carbohydrate, and less dietary cholesterol than subjects counseled only by a physician or nurse. They also had significantly greater improvement in body mass index. Both groups of subjects achieved statistically significant reductions in serum lipid levels.
Applications: Increased knowledge, benefits, and efficacy and lower-fat eating behaviors associated with additional nutrition therapy may have significant implications on the ability of persons to follow low-fat eating plans long term, which could reduce the need for costly medication intervention.