Increasing Vitamin Intake and Physical Activity

In a change setting (employees having a regular medical appointment), two interventions (one for nutrition change and one for activity change) will follow and assessments over a time period of 12 to 20 weeks will be conducted afterwards. Study participants in the intervention groups receive an interactive, computerized expert system (Intervention Group, IG). Individuals in the waiting control group (WCG) get nothing. Employees (N = 1000) will be recruited at their regular medical appointment. Study participants will be followed up over three measurement points: One to nine weeks after T1, T2 will take place. Five to 13 weeks after T1 the T3 measurement will be conducted.

The hypotheses are: In comparison to the WCG the employees in the IG are expected to have a higher motivation, to adopt a healthy lifestyle, to perform more health behavior and to be less likely to relapse into previous unhealthy routines. Also, IG employees will be healthier as well as they will report more quality of life, more work satisfaction and more occupational efficiency . In comparison to WCG, the IG is also hypothesized to be more effective than the WCG regarding social-cognitive predictors of behavior.

Moreover, the interventions are supposed to be more effective for individuals with more risk factors (obese ect.). After successful evaluation and some adoptions the intervention will be implemented as a self-help program in all eligible employees in the Intranet.

Inclusion criteria

• to be capable of exercising on their own at a minimum level and/or to consume fruits and vegetables
• able to fill out a questionnaire (no illiteracy)
• adequate German language ability

Exclusion criteria

• no internet access
• no computer with keyboard