Background. - Stages of change in exercise behaviour have been shown to be associated with health-related quality of life (HRQoL) in overweight/obese adults. However, studies examining this relationship have not used questionnaires specifically designed for such a population. The present study assessed the impact of stages of change (SOC) for exercise, using the transtheoretical model, on the HRQoL, using the Quality of Life, Obesity and Dietetics (QOLOD) scale, an obesity-specific QoL questionnaire. Our hypothesis was that the more people are in the advanced stages of behavioural change, the better their HRQoL. Methods. - A total of 214 consecutive obese individuals (148 women/66 men, mean age 47.4 +/- 14.0 years, BMI 37.2 +/- 8.4 kg/m(2)) were included in the cross-sectional study, and all completed SOC and QOLOD questionnaires. Results. - Multivariate analysis of covariance (MANCOVA) established significant effects on the overall composite of the five dimensions of the QOLOD (P<0.001). Analysis of covariance (ANCOVA) further determined the significant effect of SOC in terms of physical impact (P<0.001) and psychosocial impact (P<0.01), with marginally significant effects on sex life (P=0.07), but no impact on comfort with food (P=0.13) or on the dieting experience (P=0.13), two dimensions evaluating attitudes toward food. Conclusion. - In obese/overweight individuals, the HRQoL varies with the SOC, with those in the more advanced behavioural stages reporting better HRQoL. However, dimensions related to food showed no differences according to SOC, confirming the complexity of the relationship between exercise and nutrition, and the need for further studies to acquire a more complete understanding of their underlying mechanisms. (C) 2012 Elsevier Masson SAS. All rights reserved.