Physical Activity, Nutrition, and Obesity

ECO 2008: Oral Presentations (Abstracts T4: Behavioral Change and Patient Education PHYSICAL ACTIVITY IS ASSOCIATED WITH DECREASED EATING IN A WEIGHT MANAGEMENT PROGRAM FOR OVERWEIGHT AND OBESE WOMEN Authors: Sílvia Coutinho, Pedro Teixeira, Marlene Silva, Paulo Vieira, Margarida Castro, Teresa Santos, Luís Sardinha Abstract: PURPOSE: Physical Activity (PA) may contribute to better compliance of recommended eating behaviors, and indirectly to improved weight control. The goal of this study was to analyze the relationship between PA and changes in eating behavior psychosocial variables during a weight management program for overweight and obese women. METHODS: From 136 women (age: 38.0±7.2 years; BMI: 31.9±4.3 kg/m2) who initiated a 12-month behavioral obesity treatment program seeking to improve diet and increase PA, 120 were evaluated at 12 months. Dutch Eating Behavior Questionnaire (DEBQ), Emotional Eating Scale and the Three-Factor Eating Questionnaire were used to measure the eating behavior. The IPAQ evaluated structured PA and the OB-PAR lifestyle PA. RESULTS: During the program, subjects increased eating restriction and decreased eating disinhibition and hunger (p<0.001). p="0.026)." p="0.002)." p="0.044)." style="FONT-WEIGHT: bold">AUTONOMY, SELF-REGULATION, AND INTRINSIC MOTIVATION PREDICT SUCCESS IN A BEHAVIORAL OBESITY TREATMENT PROGRAM FOR WOMEN Authors: Marlene Silva, Paulo Vieira, Margarida Castro, Claudia Minderico, Sílvia Coutinho, Teresa Santos, Pedro Teixeira Abstract: Purpose: The goal of this study was to analyze 12-month changes in exercise-related psychosocial mediators and their impact on weight loss, in an RCT to test Self-Determination Theory (SDT) for weight management. Methods: 271 women (age, 37.5±7.1 y; BMI, 82.3±12.1 kg/m2) were assigned to intervention/control groups. The intervention group attended 30 weekly sessions designed to follow SDT. Autonomy-supportive treatment climate and internal causality orientations were predicted to enhance autonomous regulation, perceived competence, and intrinsic motivation for the targeted behaviors, resulting in lasting behavioral and body weight changes. Assessments included body weight, treatment climate (autonomy-supportive vs. controlling), and several SDT variables, some adapted to the exercise domain (exercise motivation, locus of causality, behavioral self-regulation). Results: Compared to controls, the intervention group (n=122) revealed more weight loss (p<0.001), p="0.006)," p="0.007)," p="0.001)">5% weight loss) from non-successful participants (<2% style="font-size:130%;">ECO 2008: Poster Presentations (Abstracts) T2: ISC Abstract Selected Posters TRAINING TYPE, RESTING METABOLIC RATE, AND FAT-FREE MASS IN OVERWEIGHT AND OBESE WOMEN Authors: Elvis Carnero, Pedro Teixeira, Pedro Mil-Homens, Luis Sardinha Abstract: Purpose: Controversy exists over the effect of resistance training (RT) vs. aerobic training (AT) on fat-free mass (FFM) and RMR, particularly in overweight/ obese individuals. This study was designed to analyze the relative impact of three training types (RT, AT, and AT+RT) on FFM and RMR in overweight women. Methods: Subjects were 38 healthy, sedentary, pre-menopausal, overweight women (38.9±7.0 years; BMI, 29.3±3.5 kg.m-2; %FM, 42.0±5.5%; VO2max, 31.1±4.6 ml.kg-1min-1), who were randomized into three training groups: AT, RT and AT+RT. All groups trained for 60 minutes,3 days.week-1, for 5 months. RMR was measured by indirect calorimetry. FFM was estimated with dual-energy x-ray absorptiometry (DXA). Within-group differences after 5 months were calculated and ANCOVA was performed to detect differences between groups after training, adjusting for baseline values. Results: Significant reductions in absolute (RT: -205±215; AT: -181±229; AT+RT: -110±164 kcal.day-1, p<0.05)>0.05). ANCOVA showed an effect of baseline RMR on changes after the training (absolute p<0.01, style="COLOR: rgb(204,0,0); FONT-WEIGHT: bold">T4: Behavioral Change and Patient Education ANALYSIS OF MEDIATION AND RECIPROCAL EFFECTS OF CHANGES IN WEIGHT, SELF-ESTEEM, AND EXERCISE IN A BEHAVIORAL WEIGHT LOSS TREATMENT Authors: António Palmeira, Pedro Teixeira, Marlene Silva, David Markland, Teresa Branco, Sandra Martins, Claudia Minderico, Sidónio Serpa, Luis Sardinha Abstract: Objective: To analyze reciprocal effects among self-esteem, exercise, and weight loss during (and as a result of) behavioral obesity treatment. Methods: Subjects were 144 women (BMI=31.1±4.1 kg/m2; Age=38.4±6.7 y) who attended a 12-month obesity treatment program with weekly/biweekly group sessions covering exercise, nutrition, and behavior modification topics and a randomly-assigned comparison group (n=49), receiving a general health education program. Self-esteem, exercise level, and weight were assessed at baseline and at 12 months. Multiple mediation was tested by multiple regressions, following procedures described by Preacher and Hayes (2007). Treatment vs. comparison was the independent variable, while changes in body weight, self-esteem, and exercise were analyzed alternatively as mediators and dependent variables. Results: Weight loss was greater (p<.001) in the intervention group (-5.6±6.8% vs. 1.2±4.6%). Self-esteem improved in both groups (p<.05), while the intervention group was more active at treatment’s end (p<.001). The self-esteem mediation model explained 15% of overall weight change (p<.001). Treatment total and direct effects were significant, while only the specific indirect effect of exercise was significant, suggesting that exercise partially mediated the treatment effect on weight change. The weight change mediated model explained 5% of self-esteem’s change (p=.036); treatment effects were non-significant, whereas total indirect effects and weight change’s specific indirect effects were significant, i.e., only when treatment produced weight loss did the intervention improve self-esteem. Conclusion: Results indicate the absence of reciprocal effects, suggesting that self-esteem improvements are partially caused by weight loss, while weight loss is partially affected by exercise but not by self-esteem changes. PHYSICAL ACTIVITY AND EXERCISE HISTORY: ASSOCIATIONS WITH SUCCESS IN A WEIGHT MANAGEMENT PROGRAM FOR OVERWEIGHT AND OBESE WOMEN Authors: Eliana Carraça, Pedro Teixeira, Marlene Silva, Paulo Vieira, Margarida Castro, Sílvia Coutinho, Teresa Santos, Luis Sardinha Abstract: Purpose: To analyze the relation between physical activity (PA) history and weight loss during a behavioral weight management intervention. To our knowledge, this is the first study to investigate this topic. Methods: At baseline, 116 overweight/obese women (age: 38.3±7.0 yr; BMI: 31.9±4.1 kg/m2) were randomly assigned to intervention (IG) or control groups. The IG participated in a 12-month weight management intervention seeking to improve diet and nutrition and increase physical activity. Controls received a general health education curriculum. At baseline, participants completed a PA and exercise history questionnaire. PA was categorized by exercise intensity (light, moderate, vigorous) and life period (infancy, adolescence, adulthood) and quantified in min/yr per category. Associations between PA history variables and success were analysed with correlation/regression analyses and comparing success categories at program’s end, defined as a weight loss greater than 4.9%; non-success corresponded to losing less than 2%. Results: In the IG, adolescent vigorous PA was associated with weight loss (rho=-0.25;p=0.048), and a trend was observed for total vigorous PA (rho=-0.22;p=0.081). Comparing success categories, the more successful group reported more total (p=0.001) and adult (p=0.004) vigorous PA, and more total adult PA (p=0.027). For controls only, adult (B=0.691;p=0.002) and infant (B=-0.520;p=0.017) vigorous PA were identified as negative and positive weight loss predictors, respectively. Conclusions: Results suggest PA history may predict success in weight management behavioral programs. Reporting higher levels of past vigorous activity, especially during youth, may be a prognostic marker for improved weight loss outcomes for women under behavioral obesity treatment. ARE SELF-DETERMINATION AND MOTIVATIONAL INTERVIWEING USEFUL FOR WEIGHT MANAGEMENT? RESULTS FROM A RANDOMIZED CONTROLLED TRIAL IN WOMEN Authors: Pedro Teixeira, Marlene Silva, Paulo Vieira, Cláudia Minderico, Margarida Castro, Sílvia Coutinho, Teresa Santos, Luís Sardinha Abstract: Purpose: To describe a new treatment for overweight/obese women centered around physical activity (PA) promotion and based on Self-Determination Theory (SDT) and Motivational Interviewing (MI), and report results from an ongoing 3-year RCT. Method: 257 overweight women (BMI: 31.7±4.1 kg/m2; age: 37.3±7.5 y) were randomized into intervention/control groups. The intervention included 30 weekly/bi-weekly group meetings covering PA, nutrition/eating behavior, body image, and other cognitive-behavioral contents. MI techniques were used throughout the program. Autonomous motivation and behavioral self-regulation were key intervention targets. Autonomy-supportive treatment climate and internal causality orientations were hypothesized to enhance autonomy, perceived competence, self-efficacy, and intrinsic motivation for PA, resulting in lasting behavioral and body habitus changes. Assessments included SDT-relevant putative moderators/mediators (e.g. exercise motivation, self-regulatory style), PA/exercise, dietary intake, and body weight/composition, with valid methodologies. Results: One-year results (82% retention) show the following intervention–control differences: +85±54 min/wk of total PA (p=0.112), +1518±801 steps/day (p=0.060), –5.0±0.8 in % body weight change (p<0.001), p="0.032)," p="0.032)." style="FONT-WEIGHT: bold">TESTING A NEW SELF-REPORT INSTRUMENT FOR MEASURING LIFESTYLE PHYSICAL ACTIVITY IN OBESE WOMEN Authors: Margarida Castro, Pedro Teixeira, Paulo Vieira, Marlene Silva, Claudia Minderico, Sílvia Coutinho, A. M. Silva, Teresa Santos, Luis Sardinha Abstract: Goal: To evaluate a new self-report instrument for measuring lifestyle, light, moderate, and vigorous physical activity (PA), by comparison with an accelerometry-based Activity monitor, after a behavioral weight management program in overweight/obese women. Methods: 94 women (age, 39.3±6.5 y; BMI, 29.3±4,9 kg/m2) were measured at Program’s end. Assessments included light, moderate and vigorous PA with the Actigraph GT1M and a newly-developed instrument, the Obesity-specific Physical Activity Recall (Ob-PAR), which provides increased detail within different intensity levels. This questionnaire includes a separate lifestyle PA scale. The agreement between Ob_PAR and accelerometry was explored by Spearman rank-order correlation and Bland-Altman analysis. Results: Comparing the Ob_PAR lifestyle scale with accelerometry, lifestyle PA was associated with light (min/wk) (rho=.282; p=.001) and moderate PA (min/wk) (rho=.231; p=.004) from accelerometry. Contrarily, the Ob_PAR lifestyle PA scale was negatively correlated (rho=-.218; p=.056) with sedentary behavior evaluated from accelerometry. Moderate PA (rho=.267; p=.019) and vigorous PA (rho=.252; p=.028) from Ob_PAR were correlated with moderate and vigorous PA from accelerometry, respectively. Using the Bland-Altman analysis, Ob_PAR was found to overestimate moderate (+48.2±64.1 min/day) and vigorous (+23.8±54.8 min/day) PA, compared with accelerometry (p<.001). Significant trends (p<.001) were observed between the differences of the methods and the mean of both methods, indicating underestimation at lower PA levels and overestimation at higher levels. Conclusion: The Ob_PAR lifestyle scale may be a useful tool to measure low intensity/light activities. In general, however, the main Ob_PAR questionnaire appears to overestimate PA when compared with an objective measure, displaying large limits of agreement.