Effects of a weight control intervention based on the transtheoretical model on physical activity and psychological variables in middle-aged obese women.

The study examined the effect of a weight control intervention on BMI, physical activity levels, and psychological variables toward physical activity. Thirty-three middle-aged obese women participated in the 16-week weight control intervention. Results indicated that the participants' BMI significantly decreased and physical activity levels significantly increased over the intervention. Moreover, exercise self-efficacy and perceived benefits toward physical activity significantly increased, but perceived barriers of physical activity gradually decreased over the intervention. The study suggests that it is important to consider not only physical activity itself, but also the various psychological variables when planning and implementing the weight control program.