Objectives: To evaluate the effect of a dietary treatment programme on blood cholesterol concentration in hypercholesterolaemic patients in general practice and to analyse subjectively experienced side-effects. Design: A 1-year parallel trial comparing a new treatment programme with conventional treatment. Setting: General practitioners in Roskilde county, Denmark.Subjects: 355 men and women, aged 20-60 years, with a persistent blood cholesterol concentration above age-and gender-specific cut-off points (265 in an intervention group and 90 in a control group). Intervention: A treatment strategy based on collaboration between doctor and dietitian using individual dietary advice and feedback from measured biological parameters. Main outcome measures: Serum lipids, body weight, blood pressure, dietary behaviour, health parameters, quality of life parameters and acceptance by patients and general practitioners. Results: Total blood cholesterol concentration decreased by 14% (1.07 mmol I-', P < 0.0001) in 159 patients in the intervention group, not having any lipid altering drug during treatment, in addition to 3% from screening to start of treatment. In 65 patients in the control group, without any lipid altering drug, the reduction of cholesterol concentration was 4% (0.27 mmoll-', P < 0.01; intervention vs. control P < 0.001). In the intervention group overweight subjects (body mass index > 30) reduced body weight by 6% ( P < 0.0001). Systolic blood pressure was reduced by 11% (P < 0.OOOl) and diastolic blood pressure by 10% ( P < 0.0001) and 19% ( P < 0.003) for intervals 90-110 mmHg and > 110 mmHg, respectively. Risk score decreased and self-assessed health, physical and psychological well-being improved.Conclusions: The treatment strategy tested proved to be efficient, without side-effects and well accepted by patients and general practitioners. The results strongly suggest that hypercholesterolaemia can efficiently be treated non-pharmacologically in general practice. hypercholesterolaemia should be dietary changes and the use of drugs should be considered only thereafter. The objective of this study was to evaluate a strategy for non-pharmacological treatment of patients with high risk of CHD in general practice. In addition, the impact of the intervention on objective self-assessed health, quality of life parameters, as well as its acceptance by patients and general practitioners was analysed.A parallel comparison trial, where patients from the northern and the southern community, respectively, of Roskilde county (220,000 inhabitants), Denmark were compared after 1 year of treatment. Method Patient cbaracteristicsPatients from the northern and the southern county were recruited by opportunistic screening from general practices to the intervention and the usual treatment, respectively. Virtually all GPs in the two areas participated in the study. The northern county was, for practical and logistic reasons, chosen as the intervention area since the office for the dietary intervention was located in th...