Comparison of education-only versus group-based intervention in promoting weight loss: a randomised controlled trial

Aim: To compare the effectiveness of education-only versus group-based intervention in promoting weight loss.

Methods: Between April and October 2009, a 6-month randomised controlled trial was conducted at Mito Kyodo General Hospital in Japan (UMIN000001259). The participants were 188 overweight adults (145 women, 43 men) aged 40-65 years. They were randomly assigned to one of three groups: control, moderate or intensive intervention. A single motivational lecture was provided to all three groups, educational materials (textbooks, notebooks, and a pedometer) to the moderate and intensive intervention groups, and group-based support to the intensive intervention group. Amount of weight loss was the primary outcome measure. Secondary outcome measures were components of metabolic syndrome.

Results: Mean ± SD weight loss of participants in the control, moderate and intensive intervention groups was 2.9 ± 4.1, 4.7 ± 4.0 and 7.7 ± 4.1 kg, respectively. Bonferroni post-hoc comparisons revealed all between-group differences to be significant (p < 0.05). Waist circumference decreased in the intensive intervention group more than in the other groups, whereas no significant differences were observed in the other secondary outcome measures.

Conclusion: Education-only intervention is a cost-effective method to promote weight loss. Adding group-based intervention further promotes weight loss.