Background:To examine the effects of a short-term weight reducing program on body composition, eating behaviors, and health-related quality of life (HRQL) of sedentary obese women characterized by different obesity degrees. Methods:44 women with a BMI under 34.9 kg/m² and 39 women with a BMI above 35 kg/m² were studied. Fat mass and lean mass (electrical bioimpedance), eating behaviors (Three-Factor Eating Questionnaire), and HRQL (36-item short form, SF-36, questionnaire) were determined before and after weight loss. Results:Disinhibition and hunger scores and their subscales decreased after weight loss in both groups (0.0001 < p < 0.04). Restriction increased after weight reduction in all women (p = 0.02). Among the five restriction subscales, flexible restriction increased in women with a BMI above 35 kg/m² (p = 0.008), whereas rigid restraint and avoidance of fattening foods increased in both groups (0.006 < p < 0.02). SF-36 Mental Component Score increased after weight loss in all women (p < 0.0001). Conclusion:A 3week weight reducing program changes selected eating behaviors and components of HRQL, irrespective of women’s obesity degree. Data suggest that women with a BMI above 35 kg/m² could have a better weight control in the long term because of their higher flexible restriction after weight loss when compared to those whose BMI was under 34.9 kg/m².