The effectiveness of a tailor-made intervention to prevent and reduce overweight and musculoskeletal complaints among construction workers.

The prevalence of obesity continues to increase rapidly. It is common knowledge that obesity has a negative impact on health, short term (for example musculoskeletal disorders) as well as long term (for example diabetes and cardiovascular disease). Recent research data show that the prevalence of overweight and obesity in workers in the construction industry is even higher than in the general Dutch adult population. Furthermore, in construction workers the prevalence of musculoskeletal disorders (MSD) is high. These complaints result in sickness absence and productivity loss and are possibly related to an unhealthy lifestyle.



This research project will consist of two phases. In the first phase, the intervention will be developed using an intervention mapping protocol. To increase the effectiveness and chances of successful implementation of the intervention, and the workers’ compliance, the development will take place in close cooperation with the target group and management of the organisation. The second phase of this project aims at evaluating the intervention. The additional effect of the developed lifestyle intervention compared to usual care will be investigated by means of a randomised controlled trial (RCT). Participants will be assigned randomly to two different groups: (1) a control group receiving usual care, (2) an intervention group receiving the intervention designed for this research in addition to usual care.

Measurements will take place preceding the intervention (baseline, T0), directly following the intervention (after 6 months, T1), and after 12 months (T2) to evaluate the long term effects.

Primary outcome variables are body weight and musculoskeletal complaints. Secondary outcome variables will be physical fitness, lifestyle behaviours and work-related variables such as vitality, productivity, and work ability. In addition, the cost-effectiveness of the intervention will be analysed. Finally, a process evaluation will be performed.

It is hypothesised that body weight will decrease and body composition will improve as a result of the intervention resulting from improved lifestyle and energy balance (increase in physical activity and/or lower calorie intake). Musculoskeletal complaints are expected to decrease as a result of improved physical capacity due to training and reduced body weight. In addition, an increase in physical activity will have positive effects on physical fitness, CVD risk factors, and (as a result of the positive effects mentioned above) work related measures are expected to improve.

At baseline, 6, and 12 months measurements take place.

Detailed information about the format and content of the intervention cannot be given yet, as it will be developed during the first phase of the project. Based on current literature and experience, the intervention may include the following components:

1. The intervention will be aimed at physical activity and dietary behavior (both sides of the energy balance) in order to prevent obesity and musculoskeletal complaints;

2. Respondents will receive a tailored intervention by means of specific programme materials and counselling;

3. The control group will receive care as usual.