Background: Real life implementation studies performed in different settings have proved that lifestyle interventions in the prevention of type 2 diabetes (DM2) can be effective, although the weight reduction results are typically modest compared to randomized control trials. Our objective was to identify the factors that predict successful weight loss in a less intensive, lower budget, real life setting lifestyle diabetes prevention intervention. Methods: Study participants (n = 175) with increased DM2 risk (Finnish Diabetes Risk Score (FINDRISC) > 14) but no diabetes at baseline received ten group lifestyle counselling sessions, physical activity and motivation sessions during a ten-month intervention. Stepwise regression analysis was used to determine demographic, clinical, and lifestyle predictors of successful weight reduction defined as a reduction of ≥5% of the initial body weight. Results: At 12 months following the initiation of the intervention, 23.4% of study participants lost ≥5% weight (mean loss of 7.9 kg, SD = 5.8). Increased physical activity (44% vs 25%, p = 0.03), decreased total fat consumption (88% vs 65%, p = 0.006) and adherence to four-five lifestyle goals (71% vs 46%, p = 0.007) were more often reported among those who managed to lose ≥5% weight versus those who did not. In a multivariate analysis, meeting the ≥5% weight loss goal was most effective in individuals with a higher baseline BMI (OR 1.1, 95%CI 1.0-1.2), baseline and medium versus higher education (OR 5.4, 95% CI 1.2-24.7) and a history of increased glucose (OR 2.6, 95%CI 1.1-1.3). A reduction of total fat in the diet was an independent lifestyle predictor, increasing the probability of successful weight loss by 3.8 times (OR 3.8, 95% CI 1.2-11.4). Conclusion: Baseline higher BMI, lower education and a history of increased glucose predicted the successful weight loss among individuals with a high risk for the DM2 following lifestyle intervention in a real life primary health care setting. People who manage to lose weight more often adhere to lifestyle changes, while the reduction of total fat in diet independently predicts successful weight loss. Further studies exploring the predictors of success in implementation studies in DM2 prevention should help health care providers redesign interventions to improve their effectiveness and outcomes. Trial registration: ISRCTN, ID ISRCTN96692060, registered 03.08.2016 retrospectively.
