Showing papers by "David Markland published in 2011"

Exercise Autonomous Motivation Predicts 3-yr Weight Loss in Women

Abstract: SILVA, M. N., D. MARKLAND, E. V. CARRACA, P. N. VIEIRA, S. R. COUTINHO, C. S. MINDERICO, M. G. MATOS, L. B. SARDINHA, and P. J. TEIXEIRA. Exercise Autonomous Motivation Predicts 3-yr Weight Loss in Women. Med. Sci. Sports Exerc., Vol. 43, No. 4, pp. 728–737, 2011. Purpose: This study evaluated exercise-related predictors of successful long-term weight control in women by analyzing the extent to which sustained exercise participation and self-determination theory (SDT)–based exercise motivation variables mediated the impact of a behavioral weight control intervention on 3-yr weight change. Methods: Longitudinal randomized controlled trial consisting of a 1-yr SDT-based intervention and a 2-yr follow-up with 221 female participants (means T SD: age = 37.6 T 7 yr, body mass index = 31.6 T 4.1 kgIm j2 ). The tested model incorporated experimentally manipulated perceived need support, motivational regulations, and 2-yr exercise adherence as mediators of the intervention’s impact on 3-yr weight change. Paths were tested using partial least squares analysis. Where there were significant intervening paths, tests of mediation were conducted. Results: Treatment had significant effects on 1- and 2-yr autonomous regulations, 2-yr physical activity, and 3-yr weight change, fully mediated by the tested paths (effect ratio = 0.10–0.61). Moderate and vigorous exercise at 2 yr had a significant effect (P G 0.001) on weight loss success at 3 yr and partially mediated the effect of treatment on weight change. The 2-yr autonomous regulation effects on follow-up weight change were only partially mediated by physical activity (effect ratio = 0.42). Conclusions: This application of SDT to physical activity and weight management showed that not all types of motivation predict long-term behavioral outcomes and that sustained moderate and vigorous exercise mediated long-term weight change. It provides strong evidence for a link between experimentally increased autonomous motivation and exercise and long-term weight loss maintenance. Results highlight the importance of interventions targeting the

Body image change and improved eating self-regulation in a weight management intervention in women

Abstract: Successful weight management involves the regulation of eating behavior. However, the specific mechanisms underlying its successful regulation remain unclear. This study examined one potential mechanism by testing a model in which improved body image mediated the effects of obesity treatment on eating self-regulation. Further, this study explored the role of different body image components. Participants were 239 overweight women (age: 37.6 ± 7.1 yr; BMI: 31.5 ± 4.1 kg/m2) engaged in a 12-month behavioral weight management program, which included a body image module. Self-reported measures were used to assess evaluative and investment body image, and eating behavior. Measurements occurred at baseline and at 12 months. Baseline-residualized scores were calculated to report change in the dependent variables. The model was tested using partial least squares analysis. The model explained 18-44% of the variance in the dependent variables. Treatment significantly improved both body image components, particularly by decreasing its investment component (f 2 = .32 vs. f 2 = .22). Eating behavior was positively predicted by investment body image change (p < .001) and to a lesser extent by evaluative body image (p < .05). Treatment had significant effects on 12-month eating behavior change, which were fully mediated by investment and partially mediated by evaluative body image (effect ratios: .68 and .22, respectively). Results suggest that improving body image, particularly by reducing its salience in one's personal life, might play a role in enhancing eating self-regulation during weight control. Accordingly, future weight loss interventions could benefit from proactively addressing body image-related issues as part of their protocols.

Dysfunctional body investment versus body dissatisfaction: Relations with well-being and controlled motivations for obesity treatment

Abstract: In this study, we investigated the associations between body image and psychological well-being, exploring the mediating role of controlled regulation for entering obesity treatment. In addition, we analyzed whether investment body image was more strongly associated with controlled regulation (and subsequent well-being) compared to evaluative body image. These analyses were performed controlling for baseline BMI effects. Participants were 139 overweight women (age: 38.0 ± 6.7 year; BMI: 32.0 ± 4.1 kg/m2) entering treatment. Evaluative and investment body image, controlled regulation, and psychological well-being were assessed. Body image investment was positively associated with controlled regulation; evaluative body image was not. Controlled regulation was negatively associated with self-esteem and psychological functioning. Controlled regulation partially mediated the effects of body image investment on self-esteem, but did not mediate its effects on psychological functioning. Results suggest that dysfunctional body image investment might undermine well-being within overweight women, partly by increasing controlled regulation for entering obesity treatment. Discussion focuses on the importance of enhancing body image and autonomy during treatment to improve well-being and weight outcomes.