Rationale: Lifestyle modifications, such as increasing physical exercise and reducing dietary salt and saturated fat intake contribute to prevention of cardiovascular morbidity and mortality. Relevant improvements can already be achieved by small adaptations in everyday life. It is unclear whether simple low-cost interventions in the working environment can promote such healthy lifestyle adaptations.

Objective: To study the effect of low-cost interventions for promoting healthy lifestyle modifications.

Study design: Before-and-after intervention study. The study period will be subdivided in four parts of 2 weeks each: a run-in period, a before-measurement period, an intervention-period, and an after measurement period.

Study population: Staff and visitors of the University Medical Center Utrecht.

Study interventions:

• Promotion of stair climbing.
• Promotion of a low-salt soup alternative for the 'soup of the day'.
• Promotion of a low-fat alternative for the butter croissants.
• Exchange of the basket positions of butter and margarine between convenient and harder to reach locations.

Outcome measures:

• Number of passages through each part of the stair cases.
• Number of low-salt cream soup and normal clear soup cups sold in the hospital restaurant and ratio between them.
• Number of low-fat and normal croissants sold in the hospital restaurant and the ratio between them.
• Number of low-fat margarine servings and butter servings sold in the hospital restaurant and the ratio between them.

Detailed description of the study periods:

• Run-in period: during the first 2 weeks of the study (day 1 until day 14) the baseline situation should be established and remain stable. This period is meant for study personnel to get acquainted with the study procedures.
• Before-measurement: during weeks 3 and 4 (day 15 until day 28) the measurements will start to record all endpoints and additional parameters during the baseline situation.
• Intervention-period: during weeks 5 and 6 (day 29 until day 42) the measurements will continue while the interventions are carried out.
• After measurement: during weeks 7 and 8 (day 43 until day 56) the measurements will continue while the interventions have ended and the baseline situation is restored.

Dynamic population of staff and visitors of the University Medical Center Utrecht, The Netherlands