Amsterdam Lifestyle Intervention on Food and Exercise at Work.

Block randomization was used.

In this randomized controlled trial, 1386 overweight employees are participating and being followed for two years. Participants are employees working at seven different companies throughout The Netherlands.

Subjects in the phone-based group received the healthy lifestyle intervention program in a binder and were counseled by phone; subjects in the internet-based group followed the same program on the Internet and were counseled by e-mail.
Subjects in the reference group received information brochures with general information on overweight, physical activity and healthy nutrition, and were not counseled. The intervention program lasted six months and took place in the first half year of the two years.

Measurements are taken at baseline, and at 6, 12, 18 and 24 months of follow-up.

It is hypothesized that participation in a healthy lifestyle program, aimed at controlling body weight by increasing physical activity and improving eating habits, may contribute to the reduction of overweight, to weight maintenance and consequently to the prevention of health problems, like type 2 diabetes mellitus, hypertension, hypercholesterolaemia and cardiovascular diseases.

N/A

Two intervention conditions (phone-based [N=462] or Internet-based intervention[N=464]) or a reference group (N=460);

In addition, employees were randomized to either a group of employees having basic measures only (80% out of each group) or to a group of employees having additional measures (i.e. waist circumference, body fat percentage, blood pressure, total cholesterol level and fitness level; 20% subjects of each group). The two-step randomization means there are six groups an employee could be assigned to.