RESUMEN
Background: A high fibre and moderate fat diet can reduce the metabolic risk in diabetics. This study is the first one to test which social-cognitive variables affect nutritional behaviour changes in an educational lifestyle intervention. Patients and Methods: Subjects with diabetes or at high risk (intervention: N=43; control: N=40) joined an initial and a final individual health-coaching, an 8-week comprehensive lifestyle programme und a 10-month follow-up-period. Beside anthropometric, vital und clinical parameters (e. g., weight, HbA1c, FINDRISK), behavioural stages (preintenders, intenders, actors), outcome-expectancies, action planning and self-efficacy were evaluated for a healthy diet in both groups. Results: Weight, nutritional behaviour, self-efficacy, action planning, and outcome expectancies improved in the intervention group. Improved self-efficacy after the lifestyle programme was linked to weight reduction. Discussion: The metabolic risk profile was reduced by the educational lifestyle programme. A highly developed self-efficacy seems to help to change nutritional behaviour and therefore prevent and deal with diabetes. Conclusion: Behavioural lifestyle-coachings should focus on the volitional phase and implicitly improve self-efficacy.