3. Results
T2D, weight loss, illness
The 3-year intervention was completed by 549 participants. Of 628 participants who started the intervention, 26 developed T2D before the 3-year study visit and 53 discontinued the intervention due to, e.g., illness requiring treatment, or work-related limited time resources. The participation percentage in the group meetings among all participants was 92.0–99.5%. About 55% of the participants attended also the group meetings focusing on weight loss, which were primarily provided for those having a BMI over 28 kg/mWhen the participants started, 97.6–99.5% of the participants completed the food records, whereas at the 6-month time point, the corresponding percentage was 92.6%.There were altogether over 51,000 logins to the web portal during the study, and 533 of the participants used the web portal at least once during the study. The web portal was used most actively during the first study year and there were peaks in the use close to the study visits, when food records were collected and when participants were asked to complete the tests for fiber intake, quality of dietary fat, and intake of salt in the web portal. The web portal activity is shown in Altogether, 560 participants recorded body weight and physical activity at least once during the intervention, either using the web portal or a written form (During the second and the third intervention years, the four self-feedback tasks provided on the website or via mail (