FoodSteps : The effects of a worksite environmental intervention on cardiovascular risk indicators
This dissertation describes the results of the FoodSteps project. The purpose of this project is to evaluate the effects of a relatively modest worksite environmental intervention on physical activity, food habits and biological cardiovascular risk indicators. The effects of FoodSteps study are evaluated using controlled quasi-experimental design, in which two comparable governmental companies in The Hague (The Netherlands) were used, each comprised of multi-story office building: one intervention and one control building. A worksite intervention solely based on environmental changes is relatively new. Therefore, the first chapter gives a systematic literature review to gain insight in how many and what kind of environmental worksite interventions have been performed so far. The main purpose of this review is, however, to systematically assess the effectiveness of such worksite health promotion programs on physical activity, dietary intake and health risk indicators. The FoodSteps intervention was developed and implemented, among other things based on the knowledge obtained from this review. The intervention consisted of two parts focusing on both sides of the energy balance: one part on ‘Food’ to stimulate healthy food choices and the other on ‘Steps’ (i.e., physical activity) to stimulate stair use. As there is substantial amount of scientific evidence suggesting that even small amounts or bouts of physical activity accumulated during the day can have health benefits (e.g., favorable effects on cardiovascular disease risk factors), it is essential that a simple daily physical activity like stair use is stimulated. However, it is very difficult to measure a physical activity such as stair use objectively. Moreover, no research has been performed to date to develop and validate different methods of stair use measurement. Therefore, the study as described in the second chapter has the purpose to gain insight in the comparability of self-reported stair use versus objectively measured stair use using a newly developed measuring system. The third chapter describes the short and long term effects of the ‘Steps’ intervention on stair use behavior also using this objective measuring system in a worksite environment. In the fourth chapter the effects of the combined FoodSteps intervention on biological cardiovascular disease risk indicators (i.e., BMI, blood pressure, skinfold thickness and serum cholesterol levels) are described. The fifth and the sixth chapter describe the results of FoodSteps concerning self-reported behavior regarding food habits (i.e., fruit, vegetable and fat intake) and physical activity. In the final chapter (8) the results and methods used in the FoodSteps trial are discussed and recommendations for future research and practice are made.