Health-related quality of life in obese outpatients losing weight with very-low-energy diet and behaviour modification - a 2-y follow-up study

OBJECTIVE: To study health-related quality of life (HRQL) in a clinically selected sample of obese outpatients. DESIGN: A single-strand before and after study with 2-y follow-up after treatment comprising 10 weeks on very-low-energy diet (VLED) and 4 months of behaviour modification in groups. SUBJECTS: A total of 126 (mean (s. d.) age 48.2 (11.1) y and body mass index 42.8 (6.2) kg/m(2) obese patients (63% women) referred for treatment in an obesity clinic. MEASUREMENTS: Weight and HRQL using questionnaires (RAND 36-Item Health Survey 1.0 and Obesity-related Psychosocial problems scale (OP-scale)). RESULTS: A total of 100 patients (61% women) completed the treatment and 67 (71% women) completed the 2- y follow-up. The mean ( s. d.) weight loss was 12.5 (5.6)% at the end of group therapy, 6.0 (7.1)% at 1 y, and 2.6 (7.5)% at 2 y. At baseline, the mean ( s. d.) score for the OP-scale was 61.9 (24.6). The mean scores on every RAND-36 scale were markedly lower than in the Finns without chronic conditions. All the scales in HRQL improved markedly during the treatment. During the follow-up, all the scales started to return towards baseline levels, and at 2 y only obesity-related psychosocial problems and physical functioning were still improved relative to baseline. In categories of weight change at 2 y ( greater than or equal to10% weight loss, 0 - 9.9% weight loss, weight gain), obesity-related psychosocial functioning, physical functioning, and general health showed dose - response improvement with increasing weight loss. A greater than or equal to10% weight loss at 2 y after treatment was associated with clear improvement in obesity-related psychosocial problems, physical functioning, physical role functioning, bodily pain, general health, mental health, and vitality. A 0 - 9.9% weight loss was associated with improvement in obesity-related psychosocial problems and physical functioning. Weight gain was associated with improvement in obesity-related psychosocial problems and social functioning. The study population was too small to examine possible gender differences. CONCLUSIONS: Treatment with VLED and behaviour modification produces marked short-term weight loss and clear improvement in all aspects of HRQL. At 2 y after treatment, the average maintained weight loss is modest. However, 1/3 of patients maintained a greater than or equal to5% weight loss. Improvement in obesity-related psychosocial problems and physical functioning is associated even with less than 10% of maintained weight loss. Since the pattern of HRQL changes only partly followed the pattern of weight change as expected, other factors, such as the therapeutic effect of participating in the weight loss programme or increase in physical activity, may affect HRQL responses.