Weight reduction in middle-aged women: Readiness profiles and correlates of success in a lifestyle intervention.

摘要

The studies in this dissertation were primarily designed to (a) identify pretreatment dieting/weight history and psychosocial correlates of body habitus in overweight middle-age women; (b) identify prospective readiness profiles for 4-month weight loss; and (c) examine changes in psychosocial factors are their relationship with body habitus changes. Prior to, and after a 16-week behavioral intervention, subjects completed a comprehensive psychometric battery covering 30 distinct topics relevant to weight management. The cognitive-behavioral intervention involved 16 weekly meetings covering physical activity, healthy eating, cognitive-behavior strategies, and social support, targeting a rate of weight loss of about 0.5 kg/wk. Subjects were 112 overweight and obese women (age, 47.8 ± 4.4 yrs; BMI, 31.4 ± 3.9 kg/m2; body fat, 44.7 ± 5.6%). At baseline, body weight and fat were associated with worse quality of life and physical functioning and with a poorer body image. Mean weight and %fat losses among the 89 completers were −5.4 kg and −3.4%, respectively (P 0.001). More recent dieting attempts, recent weight losses (≥10 lb), more stringent weight outcome evaluations, higher impact of weight on quality of life, lower perceived vigor and self-motivation, higher body size dissatisfaction, and lower self-esteem predicted less weight loss and significantly distinguished responders from non-responders (P 0.05). A significant discriminant function analysis showed that about 62% of subjects could be correctly classified into their corresponding tertile of weight-loss success (most and least successful tertiles only). After the intervention, completers reported significant improvements in mood, body image, and self-concept, a decrease in impact of weight on quality of life, enhanced exercise self-efficacy and motivation, and less exercise perceived barriers. Subjects reported significant increases in eating restraint, decreases in overeating/bingeing, and reduced feelings of hunger, after the program. Four-month changes in physical functioning, eating-related variables (e.g. eating restraint), exercise intrinsic motivation, and self/body-concept were among the strongest process correlates of successful weight loss. In conclusion, psychosocial readiness profiles for weight loss were identified and can predict level of outcome with moderate success. A lifestyle weight reduction program can induce marked improvements in several dimensions of women's wellness and quality of life, many of which are associated with success in short-term weight management.