a1 Department of General Practice, University of Groningen, Anton Deusinglaan, 9713 AW Groningen, the Netherlands
a2 Regional Public Health Service, GGD Groningen, Postbus 584, 9700 AN Groningen, the Netherlands
a3 Department of Human Nutrition and Epidemiology, Wageningen Agricultural University, Postbus 8129, 6700 EV Wageningen, the Netherlands
a4 TNO Nutrition and Food Research Institute, Postbus 360, 3700 AJ Zeist, the Netherlands
a5 Department of Cardiology, Groningen University Hospital, Postbus 30001, 9700 RB Groningen, the Netherlands
Objective To investigate the impact of intensive group education on the Mediterranean diet on dietary intake and serum total cholesterol after 16 and 52 weeks, compared to a posted leaflet with the Dutch nutritional guidelines, in the context of primary prevention of cardiovascular disease (CVD).
Design Controlled comparison study of an intervention group given intensive group education about the Mediterranean diet and a control group of hypercholesterolaemic persons given usual care by general practitioners (GPs).
Setting A socioeconomically deprived area in the Netherlands with an elevated coronary heart disease (CHD) mortality ratio.
Subjects Two hundred and sixty-six hypercholesterolaemic persons with at least two other CVD risk factors.
Results After 52 weeks, the intervention group decreased total and saturated fat intake more than the control group (net differences were 1.8 en% (95%CI 0.2–3.4) and 1.1 en% (95%CI 0.4–1.9), respectively). According to the Mediterranean diet guidelines the intake of fish, fruit, poultry and bread increased in the intervention group, more than in the control group. Within the intervention group, intake of fish (+100%), poultry (+28%) and bread (+6%) was significantly increased after 1 year (P < 0.05). The intensive programme on dietary education did not significantly lower serum cholesterol level more (−3%) than the posted leaflet (−2%) (net difference 0.06 mmol l−1, 95%CI −0.10 to 0.22). Initially, the body mass index (BMI) decreased more in the intervention group, but after 1 year the intervention and control group gained weight equally (+1%).
Conclusions Despite beneficial changes in dietary habits in the intervention group compared with the control group, after 1 year BMI increased and total fat and saturated fat intake were still too high.
(Received October 01 1999)
(Accepted January 07 2000)