European Congress of Obesity 2008, Geneva


The European Association for the Study of Obesity (EASO) aims to promote research into obesity, facilitate contact between individuals and organizations, and promote action that tackles the epidemic of obesity.
The European Congress of Obesity is an international, interdisciplinary conference promoted by EASO, where health professionals – clinicians, nutritionists, psychologists, and exercise scientists present their most recent work (take a look at the program). See below for abstracts and pictures from LabES members. Learn more about EASO here: http://www.easoobesity.org/



ECO 2009 Meeting in Amsterdam, The Netherlands from May 6-9.

ECO 2008 Pictures - Work!

ECO 2008 Pictures - Fun!




Sight-seeing in the historic center of Geneva,
Taking some sun after lunch on the yard next to palexpo!

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.

ACSM Annual Meeting 2008, Indianapolis

The American College of Sports Medicine Annual Meeting is a conference for the exercise sciences blending the latest research and applications for clinical sports medicine. Every year, more than 4500 attendees meet and share knowledge. This event gathers different types of researchers: physicians, exercise physiologists, nutritionists and psychologists. World-class lecturers from basic, clinical and applied sciences give symposiums and provide an updated overview of their area of interest. This meeting is also a great opportunity to present your work among your peers and network.
If you wish to know more about ACSM and future meetings go to: http://www.acsm.org/.

ACSM 2008 Pictures - Fun!

ACSM 2008, Oral Presentation (abstract)

Body Image and Quality of Life Predict Success in a 12-Month Weight Control Program

Rita Tomás, Pedro J. Teixeira, Marlene N. Silva, Paulo N. Vieira, Teresa Santos, Claúdia S. Minderico, Margarida M. Castro, Sílvia Coutinho, Miguel Marcelino, Eliana Carraça, Luís B. Sardinha
Technical University of Lisbon, Lisbon, Portugal

PURPOSE:Moderators of outcomes should be investigated, to identify weight management participants with a better chance of success, to whom resources would be more adequately allocated. The main purpose of this study was to identify baseline psychological and behavioural predictors of success in obesity treatment and identify differences between successful and unsuccessful participants in a weight control program.

METHODS:A total of 138 premenopausal women that participated in a 12-month weight control program were analyzed (age: 38.1±7 y; BMI: 31.9±4.3 kg/m2). The weight control program was cognitive-behavioral in nature, based on regular group meetings.2 to encourage progressive changes in lifestyle in domains such as eating habits and physical activity. Subjects were assessed at baseline for weight and psychological variables and body weight was also measured at the end of the intervention. Success was defined as losing 5% or more of body weight. Unsuccessful women were those who lost less than 2% of body weight or who gained weight.
RESULTS:Off all participants, 16 did not complete the program (attrition, 12%). Non-completion was associated more stringent outcome expectations (p=0.043), higher score in the Beck Depression Inventory (p=0.042), higher self-motivation (p=0.016) and higher impact of weight in quality of life (IWQoL) in self-esteem, a tendency for overall lower quality of life (p=0.064), and higher levels of trait anxiety (p=0.117). Weight reduction was correlated with better body image (rho=0.19; p=0.026) and lower IWQoL in the self-esteem domain (rho=-0.176; p=0.039). Successful losers had lower self-esteem IWQoL (p=0.003), better body image (p=0.005), lower outcome expectations (p=0.072), and fewer previous diet attempts, compared to unsuccessful participants.
CONCLUSIONS:Psychological variables such as body image, quality of life, and weight loss expectations may me useful to predict success and dropout in weight control programs. These data could also be useful to identify readiness levels for weight loss and to baseline-screen individuals matching them to interventions that better suit their characteristics.

Medicine & Science in Sports & Exercise. 40(5) Supplement 1:S84, May 2008.

Abstract #879

Topic: Energy Balance and Weight Control (605)

Session: Energy Balance and Weight Control (E-13); Free Communication/Slide

Presented: May, 30; 9:15-9:30, room 104

Chair: John M Jakicic, University of Pittsburgh, Pittsburgh, PA

E5 (Free Paper Session): Self-determination Theory

PREVIOUS WEIGHT LOSS ATTEMPTS: ASSOCIATIONS WITH SELF- DETERMINATION AND BODY IMAGE IN OVERWEIGHT AND OBESE WOMEN

Authors: Eliana Carraça- Faculty of Human Movement, Technical University of Lisbon, Marlene Silva - Faculty of Human Movement, Technical University of Lisbon , Paulo Vieira - Faculty of Human Movement, Technical University of Lisbon, Silvia Coutinho - Faculty of Human Movement, Technical University of Lisbon, Margarida Castro - Faculty of Human Movement, Technical University of Lisbon, Claudia Minderico - Faculty of Human Movement, Technical University of Lisbon, David Markland - School of Sport Health and Exercise Sciences, Bangor University, Pedro Teixeira - Faculty of Human Movement, Technical University of Lisbon

Purpose: In weight control programs, the number of previous weight loss attempts is a consistent negative moderator of success. We sought to analyze if, and by what mechanisms self-determination and body image predict previous dieting attempts, in overweight and obese women. Methods: Before starting obesity treatment, 255 women (37.5±7.1 yr; 31.6±4.1 kg/m2) completed a comprehensive body image psychosocial battery, the Self-Determination Scale (sub-scales: self-awareness, perceived choice) and a weight/dieting history questionnaire. Regression analysis, using Preacher and Hayes (2007) procedures to test indirect/mediated effects, were used for statistical analyses. Results: Previous weight loss attempts (WLA) were predicted by body shape concerns (BSC, r=0.34; p<0.001), r="-0.15;" p="0.035)," r="0.16;" p="0.021)," r="0.25;" r="-0.45;">

EXERCISE INTRINSIC MOTIVATION, AUTONOMOUS SELF-REGULATION, AND PSYCHOLOGICAL MOTIVES AS MEDIATORS OF PHYSICAL ACTIVITY DURING WEIGHT MANAGEMENT

Authors: Marlene Silva - Faculty of Human Movement, Pedro Teixeira - Faculty of Human Movement, Paulo Vieira - Faculty of Human Movement, Margarida Castro - Faculty of Human Movement, Claudia Minderico - Faculty of Human Movement, Silvia Coutinho - Faculty of Human Movement, Antonio Palmeira - Universidade Lusofona de Humanidades e Tecnologias, David Markland - Bangor University

Purpose: To analyse the role of exercise intrinsic motivation (IM), locus of causality (LC), autonomous self-regulation (ASR), and psychological motives (PM) as mediators of physical activity (PA) during an obesity treatment program based on Self-Determination Theory (SDT). Methods: 255 women (37.5±7.1y; 31.6±4.2kg/m2) participated and were assigned to intervention/control groups. The intervention (30 weekly sessions) was specifically designed to increase PA, following SDT principles. Controls received a general health education program. Assessments included putative SDT mediators and PA: walking, moderate + vigorous PA (7-day PAR), and lifestyle PA. Multiple regression was used to test for mediation, as forwarded by Baron and Kenny. Indirect/mediated effects were tested using procedures described by Preacher and Hayes (2007). Results: The intervention significantly changed all putative SDT mediators (p<0.001) p="0.017).">

SUCCESSFUL APPLICATION OF SELF-DETERMINATION THEORY TO BEHAVIORAL WEIGHT MANAGEMENT: RESULTS FROM A RANDOMIZED CONTROLLED TRIAL IN WOMEN

Authors: Pedro J. Teixeira - Faculty of Human Movement, Marlene N. Silva - Faculty of Human Movement, Paulo N. Vieira - Faculty of Human Movement, Claudia S. Minderico - Faculty of Human Movement, Margarida M. Castro - Faculty of Human Movement, Silvia Coutinho - Faculty of Human Movement, Teresa Santos - Faculty of Human Movement, Luis B Sardinha - Faculty of Human Movement

Purpose: To describe a weight management program for overweight/obese women centered on physical activity (PA) and based on Self-Determination Theory, and report results for key intervention outcomes. Method: 255 women (37.5±7.1y; 31.6±4.1kg/m2) were randomized into intervention/control groups. The program included 30 weekly/bi-weekly group meetings; autonomous motivation and a more internal PA/diet behavioral regulation were targeted. The autonomy-supportive treatment climate was hypothesized to enhance self-determination, perceived competence, and intrinsic motivation for PA, aiming for lasting behavioral/weight changes. Physical activity (7-day PAR, Ob-PAR) and weight were assessed at baseline and 12 months (83.2% retention). Mediation analysis was tested with multiple regression and indirect effects estimated with the Preacher and Hayes procedure. Results: Intervention-control differences for 12-month changes were: +94±28 min/wk for moderate + vigorous PA, +108±34 min/wk for walking, ES=0.88 for a lifestyle PA index, and -5.0±0.8% for body weight (p<0.003 p="0.002)," r="-0.33," r="-0.15," p="0.032)," r="-0.25," p="0.001)" p="0.005">

ANALYSIS OF RECIPROCAL EFFECTS BETWEEN CHANGES IN WEIGHT AND BODY IMAGE IN A BEHAVIORAL WEIGHT LOSS TREATMENT

Authors: Antonio L. Palmeira - Universidade Lusofona de Humanidades e Tecnologias, Pedro J. Teixeira - Faculty of Human Movement, Technical University of Lisbon, Marlene N Silva - Faculty of Human Movement, Technical University of Lisbon, David A. Markland - Bangor University, Teresa L. Branco - Faculty of Human Movement, Technical University of Lisbon, Sandra Martins - Faculty of Human Movement, Technical University of Lisbon, Claudia Minderico - Faculty of Human Movement, Technical University of Lisbon, Luis B. Sardinha - Faculty of Human Movement, Technical University of Lisbon

Purpose: To analyse the reciprocity between changes in weight and changes in body shape concerns (BSC), analyzed alternatively as a mediator and an outcome, during a behavioral obesity treatment program in women. Methods: Subjects (BMI=31.1±4.1 kg/m2; Age=38.4±6.7 y) were 144 women who attended a 12-month obesity treatment program and a comparison group (n=49), who received a general health education program. Weight, BSC and exercise level were assessed at baseline and 12-months. Multiple mediation was tested by multiple regression, analyzing total/direct/indirect effects of each variable, while controlling for other mediators (see Preacher & Hayes, 2007). Treatment/comparison was the independent variable, exercise was analyzed as a mediator, while changes in weight and BSC were analyzed alternatively as mediators and dependent variables. Results: Weight loss was greater in the treatment group (-5.6±6.8% vs. 1.2±4.6%, p<.001). Both groups improved their body image (p<.001) and the intervention group was more active at treatment's end (p<.001). The BSC mediation model explained 24% of weight change (p<.001). Total, direct, and total indirect effects were significant, suggesting that changes in BSC partially mediated treatment effects on weight. The weight change mediation model explained 17% of treatment-induced change in BSC (p<.001). The specific indirect effects showed that weight change completely mediated change in body image. Exercise was not a mediator in either model. Conclusion: The reciprocal effects hypothesis was confirmed; changes in weight and body image appear to influence each other during the course treatment, adjusting for physical activity. The strongest effect was observed for weight as a mediator of changes in concerns with body shape and feelings of being too fat.

A Sessions: Symposia
A1: The Scale Is The Limit? Weighing Obesity Interventions from an Ethical Perspective. Chair: Sofie Vandamme, Department of Medical Ethics and Philosophy, Erasmus MC, Rotterdam, The Netherlands

“You Should Lose Weight!”: A Note Of (Evidence-Based) Caution Before You Say These Words

Authors: Teixeira, Pedro

Abstract: Purpose: For those involved in treatment obesity, such as behavioral/lifestyle therapies, facing questions with ethical implications is common. This presentation will identify critical decisions to be made before/during treatment, highlight relevant research findings, and provide ethically-sound recommendations. Methods: Empirical and theoretical support for this presentation comes from the author's clinical/practical experience and from key/representative studies available in the obesity literature. Results: Recommending that someone loses weight (and advising on how to do it) generally assumes the expert/provider to be sufficiently certain about the following aspects, among others: i) When is body weight/fat more likely to impair physical health? The weight-morbidity association is strong only at the highest obesity levels, and effect-moderators (e.g., physical activity) exist and must be considered; ii) How much weight loss can realistically be "promised"? The best studies show... not a lot (beyond 5%)! However, predictor studies provide some guidance on maximizing (and/or anticipating) individual success level; iii) How to deal with very high weight loss goals? Evidence suggests more intrinsic motivations and moderate expectations may pay off; iv) What is the most effective treatment? The one that succeeds in increasing physical activity adherence; v) How long should treatment last? According to the (limited) evidence, the longer the better; but alternatives to continuous care should be sought; vi) Are there risks of weight loss? They can be minimized and do not outweigh benefits. Conclusion: Only by adequately addressing these (and other) questions can the provider intervene more ethically: disclose all relevant information, provide choice, not cause harm, effectively allocate limited resources, keep the patient's best interest (and dignity) in mind, and support his/her autonomy.

B1: It’s About Time: Modeling Real-Time Assessment Data on Physical Activity and Nutrition.

Chair: Jutta Mata, Faculty of Human Movement – Technical University of Lisbon, Lisbon, Portugal & Max Planck Institute for Human Development, Berlin, Germany; Mark Pereira, University of Minnesota, Minneapolis, MN, USA

Using Ecological Momentary Assessment To Understand The Role Of Psychosocial And Environment Factors In Weight Control

Authors: Mata, Jutta; Santos, Teresa; Vieira, Paulo N. ; Silva, Marlene N.; Coutinho, Silvia; Teixeira, Pedro J.

Abstract: Purpose: The determinants of successful weight loss in previously overweight people are not fully understood. This study uses a process-oriented instrument, Ecological Momentary Assessment (EMA), which measures behaviors, states, and ecological influences on a daily level to 1) investigate how daily fluctuations in exposure to environments facilitating physical activity (PA) and healthy nutrition are related to fluctuations in behavior-specific self-efficacy and 2) compare differences in day-to-day self-efficacy in participants with high versus low weight loss. Methods Over two 2-week periods during a behavioral weight control program, 47 overweight women filled out questions on psychosocial variables (including self-efficacy) related to PA, nutrition, situational, and ecological factors on a daily level. Coefficients of variation were used to study associations between intra-individual fluctuation in PA- and nutrition-related self-efficacy and environments facilitating these behaviors. Differences in self-efficacy between participants with high and low 4-month weight loss were determined using Multilevel Modeling. Results: Daily fluctuations in behavior-specific self-efficacy were significantly correlated with exposure to environments facilitating them (r(PA)=.51, r(nutrition)=.26, p<.001). Multilevel models showed that nutrition self-efficacy over two weeks was higher in people with high weight loss (p<.05). However, there was no difference between the groups in PA-related self-efficacy (p=.81). Conclusions: This study highlights two methods that can be used to analyze EMA data. Results provide insight into the process underlying associations between exposure to specific environments and fluctuations in psychosocial factors, and the importance of daily-level nutrition self-efficacy for initial weight loss success.

ISBNPA 2008 Meeting, Banff

The meeting of the International Society for Behavioral Nutrition and Physical Activity is an international, interdisciplinary conference where exercise scientists, nutritionists and psychologists present their most recent work (take a look at the program). See below for abstracts and pictures from LabES members.Learn more about ISBNPA here: http://www.isbnpa.org/

ISBNPA 2009 Meeting in Lisbon, Portugal - presentation by Pedro Teixeira

Hand over of the conference bell to the next "Chair" of ISBNPA, Pedro Teixeira. See you at next year's ISBNPA meeting in Cascais (Lisbon,Portugal) from June 17-20!






Dont´t miss the satellite Meeting on Self-Determination Theory (Understanding and Changing Health Behavior with Self-Determination Theory and Motivational Interviewing)June 21-23. Here you see the heads of the satellite meeting organization team! António Palmeira & David Markland.

ISBNPA 2008 Pictures- Fun!

Taking a bath in the Hot Springs; Dinning at the most Canadian restaurants; Time togheter...

ISBNPA 2008 Pictures - Work!

Some pictures of the congress and the LABES team "in action"!

ISBNPA 2008: Oral Presentations (Abstracts)

E5 (Free Paper Session): Self-determination Theory PREVIOUS WEIGHT LOSS ATTEMPTS: ASSOCIATIONS WITH SELF- DETERMINATION AND BODY IMAGE IN OVERWEIGHT AND OBESE WOMEN Authors: Eliana Carraça- Faculty of Human Movement, Technical University of Lisbon, Marlene Silva - Faculty of Human Movement, Technical University of Lisbon , Paulo Vieira - Faculty of Human Movement, Technical University of Lisbon, Silvia Coutinho - Faculty of Human Movement, Technical University of Lisbon, Margarida Castro - Faculty of Human Movement, Technical University of Lisbon, Claudia Minderico - Faculty of Human Movement, Technical University of Lisbon, David Markland - School of Sport Health and Exercise Sciences, Bangor University, Pedro Teixeira - Faculty of Human Movement, Technical University of Lisbon Purpose: In weight control programs, the number of previous weight loss attempts is a consistent negative moderator of success. We sought to analyze if, and by what mechanisms self-determination and body image predict previous dieting attempts, in overweight and obese women. Methods: Before starting obesity treatment, 255 women (37.5±7.1 yr; 31.6±4.1 kg/m2) completed a comprehensive body image psychosocial battery, the Self-Determination Scale (sub-scales: self-awareness, perceived choice) and a weight/dieting history questionnaire. Regression analysis, using Preacher and Hayes (2007) procedures to test indirect/mediated effects, were used for statistical analyses. Results: Previous weight loss attempts (WLA) were predicted by body shape concerns (BSC, r=0.34; p<0.001), physical self-worth (PSW, r=-0.15; p=0.035), social physique anxiety (SPA, r=0.16; p=0.021), and fear of negative appearance evaluation (FNAE, r=0.25; p<0.001); 13% of the variance in WLA was explained in multiple regression (p<0.001). Self-awareness was significantly related to all body image measures, with the strongest effect observed for BSC (r=-0.45; p<0.001). There were no significant total or direct effects of self-determination on WLA. However, indirect effects of self-awareness through BSC, SPA, and FNAE were significant (p<0.05). For perceived choice, significant indirect effects were observed only for BSC. Conclusion: Recent dieting attempts are strongly related to poor body image. Mediation analysis suggests that awareness of self may hold an indirect effect on dieting attempts through body image. Results are consistent with the hypothesis that reduced self-awareness contributes to body dissatisfaction, which in turn increases the desire to diet and/or lose weight. This trial will continue to explore mechanisms that might explain repeated dieting attempts. EXERCISE INTRINSIC MOTIVATION, AUTONOMOUS SELF-REGULATION, AND PSYCHOLOGICAL MOTIVES AS MEDIATORS OF PHYSICAL ACTIVITY DURING WEIGHT MANAGEMENT Authors: Marlene Silva - Faculty of Human Movement, Pedro Teixeira - Faculty of Human Movement, Paulo Vieira - Faculty of Human Movement, Margarida Castro - Faculty of Human Movement, Claudia Minderico - Faculty of Human Movement, Silvia Coutinho - Faculty of Human Movement, Antonio Palmeira - Universidade Lusofona de Humanidades e Tecnologias, David Markland - Bangor University Purpose: To analyse the role of exercise intrinsic motivation (IM), locus of causality (LC), autonomous self-regulation (ASR), and psychological motives (PM) as mediators of physical activity (PA) during an obesity treatment program based on Self-Determination Theory (SDT). Methods: 255 women (37.5±7.1y; 31.6±4.2kg/m2) participated and were assigned to intervention/control groups. The intervention (30 weekly sessions) was specifically designed to increase PA, following SDT principles. Controls received a general health education program. Assessments included putative SDT mediators and PA: walking, moderate + vigorous PA (7-day PAR), and lifestyle PA. Multiple regression was used to test for mediation, as forwarded by Baron and Kenny. Indirect/mediated effects were tested using procedures described by Preacher and Hayes (2007). Results: The intervention significantly changed all putative SDT mediators (p<0.001) and increased PA (moderate + vigorous, lifestyle PA, p<0.001; walking, p=0.017). In the mediated models through IM, LC, ASR, and PM the intervention direct effects on moderate-vigorous and lifestyle PA were reduced but remained significant. Significant (p<0.05) indirect effects were observed through all 4 SDT variables, suggesting partial mediation. For walking, only psychological motives (i.e., enjoyment, challenge, energy) partially mediated intervention effects. Conclusion: The utility of mediation analysis in interventions stems from its ability to go beyond the descriptive to a more functional understanding of the true mechanisms of psychological and behavioral change. The present results are consistent with autonomous self-regulation and intrinsic motivation resting within the causal path of exercise adherence during weight control. Furthermore, they support SDT as a promising theoretical framework to promote health behavior change. SUCCESSFUL APPLICATION OF SELF-DETERMINATION THEORY TO BEHAVIORAL WEIGHT MANAGEMENT: RESULTS FROM A RANDOMIZED CONTROLLED TRIAL IN WOMEN Authors: Pedro J. Teixeira - Faculty of Human Movement, Marlene N. Silva - Faculty of Human Movement, Paulo N. Vieira - Faculty of Human Movement, Claudia S. Minderico - Faculty of Human Movement, Margarida M. Castro - Faculty of Human Movement, Silvia Coutinho - Faculty of Human Movement, Teresa Santos - Faculty of Human Movement, Luis B Sardinha - Faculty of Human Movement Purpose: To describe a weight management program for overweight/obese women centered on physical activity (PA) and based on Self-Determination Theory, and report results for key intervention outcomes. Method: 255 women (37.5±7.1y; 31.6±4.1kg/m2) were randomized into intervention/control groups. The program included 30 weekly/bi-weekly group meetings; autonomous motivation and a more internal PA/diet behavioral regulation were targeted. The autonomy-supportive treatment climate was hypothesized to enhance self-determination, perceived competence, and intrinsic motivation for PA, aiming for lasting behavioral/weight changes. Physical activity (7-day PAR, Ob-PAR) and weight were assessed at baseline and 12 months (83.2% retention). Mediation analysis was tested with multiple regression and indirect effects estimated with the Preacher and Hayes procedure. Results: Intervention-control differences for 12-month changes were: +94±28 min/wk for moderate + vigorous PA, +108±34 min/wk for walking, ES=0.88 for a lifestyle PA index, and -5.0±0.8% for body weight (p<0.003 for all). At 12 months, 170 women (66.1%) were sufficiently active (-5.9±6.4% weight vs. -2.5±6.4% for inactive, p=0.002), of which 62% were in the intervention group. Moderate + vigorous PA (r=-0.33, p<0.001), walking (r=-0.15, p=0.032), and lifestyle PA (r=-0.25, p=0.001) predicted weight loss, but only moderate + vigorous PA (partially) mediated intervention effects on weight change (p=0.005 for indirect effects). Conclusion: Self-Determination Theory has not been previously applied to weight management in a long-term, experimental, controlled design. The present findings indicate that this results in intervention-related, meaningful changes in physical activity/exercise and body weight, two hallmarks of successful obesity treatment. ANALYSIS OF RECIPROCAL EFFECTS BETWEEN CHANGES IN WEIGHT AND BODY IMAGE IN A BEHAVIORAL WEIGHT LOSS TREATMENT Authors: Antonio L. Palmeira - Universidade Lusofona de Humanidades e Tecnologias, Pedro J. Teixeira - Faculty of Human Movement, Technical University of Lisbon, Marlene N Silva - Faculty of Human Movement, Technical University of Lisbon, David A. Markland - Bangor University, Teresa L. Branco - Faculty of Human Movement, Technical University of Lisbon, Sandra Martins - Faculty of Human Movement, Technical University of Lisbon, Claudia Minderico - Faculty of Human Movement, Technical University of Lisbon, Luis B. Sardinha - Faculty of Human Movement, Technical University of Lisbon Purpose: To analyse the reciprocity between changes in weight and changes in body shape concerns (BSC), analyzed alternatively as a mediator and an outcome, during a behavioral obesity treatment program in women. Methods: Subjects (BMI=31.1±4.1 kg/m2; Age=38.4±6.7 y) were 144 women who attended a 12-month obesity treatment program and a comparison group (n=49), who received a general health education program. Weight, BSC and exercise level were assessed at baseline and 12-months. Multiple mediation was tested by multiple regression, analyzing total/direct/indirect effects of each variable, while controlling for other mediators (see Preacher & Hayes, 2007). Treatment/comparison was the independent variable, exercise was analyzed as a mediator, while changes in weight and BSC were analyzed alternatively as mediators and dependent variables. Results: Weight loss was greater in the treatment group (-5.6±6.8% vs. 1.2±4.6%, p<.001). Both groups improved their body image (p<.001) and the intervention group was more active at treatment's end (p<.001). The BSC mediation model explained 24% of weight change (p<.001). Total, direct, and total indirect effects were significant, suggesting that changes in BSC partially mediated treatment effects on weight. The weight change mediation model explained 17% of treatment-induced change in BSC (p<.001). The specific indirect effects showed that weight change completely mediated change in body image. Exercise was not a mediator in either model. Conclusion: The reciprocal effects hypothesis was confirmed; changes in weight and body image appear to influence each other during the course treatment, adjusting for physical activity. The strongest effect was observed for weight as a mediator of changes in concerns with body shape and feelings of being too fat. A Sessions: Symposia A1: The Scale Is The Limit? Weighing Obesity Interventions from an Ethical Perspective. Chair: Sofie Vandamme, Department of Medical Ethics and Philosophy, Erasmus MC, Rotterdam, The Netherlands “You Should Lose Weight!”: A Note Of (Evidence-Based) Caution Before You Say These Words Authors: Teixeira, Pedro Abstract: Purpose: For those involved in treatment obesity, such as behavioral/lifestyle therapies, facing questions with ethical implications is common. This presentation will identify critical decisions to be made before/during treatment, highlight relevant research findings, and provide ethically-sound recommendations. Methods: Empirical and theoretical support for this presentation comes from the author's clinical/practical experience and from key/representative studies available in the obesity literature. Results: Recommending that someone loses weight (and advising on how to do it) generally assumes the expert/provider to be sufficiently certain about the following aspects, among others: i) When is body weight/fat more likely to impair physical health? The weight-morbidity association is strong only at the highest obesity levels, and effect-moderators (e.g., physical activity) exist and must be considered; ii) How much weight loss can realistically be "promised"? The best studies show... not a lot (beyond 5%)! However, predictor studies provide some guidance on maximizing (and/or anticipating) individual success level; iii) How to deal with very high weight loss goals? Evidence suggests more intrinsic motivations and moderate expectations may pay off; iv) What is the most effective treatment? The one that succeeds in increasing physical activity adherence; v) How long should treatment last? According to the (limited) evidence, the longer the better; but alternatives to continuous care should be sought; vi) Are there risks of weight loss? They can be minimized and do not outweigh benefits. Conclusion: Only by adequately addressing these (and other) questions can the provider intervene more ethically: disclose all relevant information, provide choice, not cause harm, effectively allocate limited resources, keep the patient's best interest (and dignity) in mind, and support his/her autonomy. B1: It’s About Time: Modeling Real-Time Assessment Data on Physical Activity and Nutrition. Chair: Jutta Mata, Faculty of Human Movement – Technical University of Lisbon, Lisbon, Portugal & Max Planck Institute for Human Development, Berlin, Germany; Mark Pereira, University of Minnesota, Minneapolis, MN, USA Using Ecological Momentary Assessment To Understand The Role Of Psychosocial And Environment Factors In Weight Control Authors: Mata, Jutta; Santos, Teresa; Vieira, Paulo N. ; Silva, Marlene N.; Coutinho, Silvia; Teixeira, Pedro J. Abstract: Purpose: The determinants of successful weight loss in previously overweight people are not fully understood. This study uses a process-oriented instrument, Ecological Momentary Assessment (EMA), which measures behaviors, states, and ecological influences on a daily level to 1) investigate how daily fluctuations in exposure to environments facilitating physical activity (PA) and healthy nutrition are related to fluctuations in behavior-specific self-efficacy and 2) compare differences in day-to-day self-efficacy in participants with high versus low weight loss. Methods Over two 2-week periods during a behavioral weight control program, 47 overweight women filled out questions on psychosocial variables (including self-efficacy) related to PA, nutrition, situational, and ecological factors on a daily level. Coefficients of variation were used to study associations between intra-individual fluctuation in PA- and nutrition-related self-efficacy and environments facilitating these behaviors. Differences in self-efficacy between participants with high and low 4-month weight loss were determined using Multilevel Modeling. Results: Daily fluctuations in behavior-specific self-efficacy were significantly correlated with exposure to environments facilitating them (r(PA)=.51, r(nutrition)=.26, p<.001). Multilevel models showed that nutrition self-efficacy over two weeks was higher in people with high weight loss (p<.05). However, there was no difference between the groups in PA-related self-efficacy (p=.81). Conclusions: This study highlights two methods that can be used to analyze EMA data. Results provide insight into the process underlying associations between exposure to specific environments and fluctuations in psychosocial factors, and the importance of daily-level nutrition self-efficacy for initial weight loss success.