BACKGROUND: Healthy diet is a core component in prevention and self-management of type 2 diabetes and cardiovascular disease. The long-term efficacy was assessed of a theory-based health education programme 'Ready to Act' on dietary quality in people with screen-detected dysglycaemia.

METHODS: Five hundred and nine adults with prediabetes (impaired glucose tolerance, impaired fasting glycaemia) or type 2 diabetes were recruited through screening for type 2 diabetes [the ADDITION (Anglo-Danish-Dutch Study of Intensive Treatment in People with Screen-Detected Diabetes in Primary Care) study, DK] and then randomly assigned to health education or to a control group (I = 322; C = 187). The intervention group was offered a 12-week programme in health-related action competence including 2 one-to-one and 8 group sessions (18 h). Dietary quality was measured by the Dietary Quality Score_revised (0-8 points) at baseline and at one- and 3-year follow-up. Changes were analysed by multilevel analyses.

RESULTS: The analysis included data from 444 participants (87%). At the 3-year follow-up, the intervention group had significantly increased dietary quality compared with the control group (net change: 0.39 Dietary Quality Score_revised points, P = 0.04). The intake of unsaturated fats used on bread and for cooking increased in the intervention group compared with the control group at the 3-year follow-up (net change: 31 g/week; P = 0.02). A non-significant tendency toward an increased intake of vegetables in the intervention group compared with the control group was seen (net change: 111 g/week; P = 0.16). No changes were seen in fish intake.

CONCLUSIONS: Health education aiming at action competence improved the long-term dietary quality in a population with dysglycaemia, especially according to the intake of unsaturated fat. The ADDITION trial was registered at ClinicalTrials.gov ID no NCT00237549.