Objective: To study health-related quality of life responses to marked weight loss in WHO Class II-III (body mass index (BMI) > or = 35 kg/m2) obese men.
Design: An 8 month randomised clinical trial with a 4 month weight loss programme (10 weeks on a very-low-energy diet (VLED) and 17 behaviour modification visits) in the treatment group and no intervention in the control group.
Subjects: Nineteen men (mean age 45.9 y, mean BMI 39.3 kg/m2) in the treatment group and 19 men (47.2 y, 39.4 kg/m2) in the control group.
Measurements: Weight and questionnaires measuring health-related quality of life (RAND 36-Item Health Survey 1.0 and obesity-related psychosocial problems scale).
Results: In the treatment group, the mean (s.d.) weight loss was 17.0 (7.4)% at the end of the 4 month therapy. At the end of follow-up, nearly 6 months after the end of VLED in the treatment group, the average maintained weight loss was 13.9 (7.8)% of baseline weight. The control group was weight stable throughout the study. During treatment, there was only transient improvement in general health, bodily pain, mental health, emotional role functioning and vitality (all increases in the scores were not statistically significant). Improvements in physical functioning, social functioning and obesity-related psychosocial problems were maintained until the end of follow-up. The treatment group also reported improvement in perceived health in the past year. There was only minor fluctuation in questionnaire scores in the control group.
Conclusion: The short-term and maintained health-related quality of life effects of weight loss may differ. Marked weight loss in WHO Class II-III obese men leads to improvements in physical functioning, social functioning, obesity-related psychosocial problems, and perceived health; these improvements were maintained at 4 month post-intervention follow-up.