The Cordon study of weight reduction based on behaviour modification.

A behaviour modification programme for the treatment of obesity was offered to a population of obese women, aged 51-67, being screened for breast cancer. The programme was offered in two forms: (1) A series of ten small group sessions under the guidance of a non-medical leader, with three follow-up meetings after the course (10 S programme). (2). A series of ten mailed lessons with a pre- and post-course interview and three follow-up meetings after the course (10 L programme). The drop-out rate during the course was 12 per cent for the 10 S programme and 37 per cent for the 10 L programme. Follow-up in the 10 S programme revealed an average weight loss of 5.2 kg after 3 months, 4.1 kg after 17 months, and 3.0 kg after 36 months. Comparable figures in the 10 L programme were 3.0 kg, 3.0 kg and 1.6 kg, respectively. Percentile distributions of weight loss after these intervals are presented. Results are compared with those in other obese women in the cancer screening programme who either had no plans for weight reduction or said they had opted for other kinds of intervention. These comparisons clearly favour the behaviour treatment programme, but the picture may have been influenced by a possibly higher motivation of those who followed the course.