Characteristics of successful weight reducers: a brief review of predictor variables

Development and validation of prognostic models to estimate body weight loss in overweight and obese people

Introduction

Background: predicting weight loss outcomes from information collected from subjects before they start a weight management program is an objective strongly pursued by scientists who study energy balance. Objective: to develop and validate two prognostic models for the estimation of final body weight after a six-month intervention period. Material and methods: the present work was developed following the TRIPOD standard to report prognostic multivariable prediction models. A multivariable linear regression analysis was applied to 70 % of participants to identify the most relevant variables and develop the best prognostic model for body weight estimation. Then, 30 % of the remaining sample was used to validate the model. The study involved a 6-month intervention based on 25-30 % caloric restriction and exercise. A total of 239 volunteers who had participated in the PRONAF study, aged 18 to 50 years, with overweight or obesity (body mass index: 25-34.9 kg/m2), were enrolled. Body composition was estimated by dual-energy X-ray absorptiometry (DXA) and by hand-to-foot bioelectrical impedance (BIA) analysis. Results: prognostic models were developed and validated with a high correlation (0.954 and 0.951 for DXA and BIA, respectively), with the paired t-tests showing no significant differences between estimated and measured body weights. The mean difference, standard error, and 95 % confidence interval of the DXA model were 0.067 ± 0.547 (-1.036-1.170), and those of the BIA model were -0.105 ± 0.511 (-1.134-0.924). Conclusions: the models developed in this work make it possible to calculate the final BW of any participant engaged in an intervention like the one employed in this study based only on baseline body composition variables.

Overweight and obese adults have low intentions of seeking weight-related care: a cross-sectional survey

BACKGROUND

The prevalence of obesity is growing worldwide. Obesity guidelines recommend increasing the level of weight-related care for persons with elevated levels of weight-related health risk (WRHR). However, there seems to be a discrepancy between need for and use of weight-related care. The primary aim of this study is to examine predisposing factors that may influence readiness to lose weight and intention to use weight-related care in an overweight population.

METHODS

A population-based, cross-sectional survey was conducted. Data were collected using an online self-administered questionnaire sent to a population-representative sample of 1,500 Dutch adults on the Health Care Consumer Panel (n = 861 responded). Data were used from individuals (n = 445) with a mildly, moderately or severely elevated level of WRHR. WRHR status was based on self-reported data on Body Mass Index, risk assessment for diabetes mellitus type 2 (DM2) and cardiovascular disease (CVD), or co-morbidities.

RESULTS

55.1% of persons with increased WRHR were ready to lose weight (n = 245). Depending on level of WRHR; educational level, marital status, individuals with an accurate perception of their weight and better perceptions and expectations of dietitians were significantly related to readiness to lose weight. Most of them preferred individual weight-loss methods (82.0% of n = 245). 11% (n = 26 of n = 245) intended to use weight-related care. Weight-related care seeking was higher for those with moderate or severe WRHR. Expectations and trust in dietitians did not seem to influence care seeking.

CONCLUSIONS

Many Dutch adults who are medically in need of weight-related care are ready to lose weight. Most intend to lose weight individually, and only a few intend to use weight-related care. Therefore, obesity prevention initiatives should focus on monitoring weight change and weight-loss plans, and timely referral to obesity management. However, many people are not ready to lose weight. For this group, strategies for behaviour change may depend on WRHR, perceptions of weight and dietitians, educational level and marital status. Obesity prevention initiatives should focus on increasing the awareness of the seriousness of their condition and offering individually appropriate weight management programmes.

Factors Associated with Weight Control in Older Adults

Dieting behaviors in a sample of 183 overweight older adults were studied to assess how they were influenced by six cognitive, behavioral, emotional, and social variables. Membership in a weight control program was also evaluated to assess whether it affected these relationships. Responses indicated that reports of high quality dieting behaviors were associated with higher levels of depression and less effective coping skills. Dieting behaviors among subjects who were participants in weight loss programs were not as strongly associated with less effective coping skills, but were associated with external health locus-of-control. The degree of social support had a limited impact on dieting behaviors, while measures of optimism and health status were unrelated to dieting behaviors. We concluded that older adults, especially those who diet independently, are likely to experience significant stress associated with weight loss efforts. Weight loss programs for older adults might produce better outcomes if they focus on reducing depression and stress associated with dieting.

Getting access to the self: Effects of self-management therapy on the development of self-regulation and inhibitory control in obese adolescents

BACKGROUND AND AIMS

This study investigated the role of self-regulation competencies in general and specifically in a food-related context for the control of body weight in a three-year weight loss program.

METHODS

The sample consisted of 30 male and female adolescents (age range: 11-18 years) who participated in a three-year therapy program for severe obesity (mean BMI at the beginning of the intervention was 33.6). Assessment of self-regulation competencies was conducted at three different stages (1(st)-3(rd) graduation/class year). Therefore, three independent groups of adolescents (N = 10) at these different stages were tested (initial-to final-stage of therapy). At the time of testing the BMI of these groups significantly differed from 38.8 to 28.7. Analyses of covariance were performed to determine whether the adolescents also differed in self-regulation skills like "resistance to temptation" and food-related Stroop interference along with ameliorating their energy-balance regulation.

RESULTS

In addition to the main effects of age and body mass index, adolescents further displayed significant improvements of executive functions with respect to resistance to temptation and inhibition.

CONCLUSIONS

Interventions aimed at enhancing energy-balance regulation in adolescents may further benefit from efforts to facilitate executive functions such as self-regulation and food-related cognitive inhibition.

Motivational readiness to change in lifestyle modification programs

Weight management programs still remain a great challenge as drop out rates represent a growing problem. It is essential to try and identify the predictors of success, in order to make a proposal really custom-tailored to the patients. Among the most valuable applications of valid weight loss prediction models is the early identification of individuals with the least estimated probability of success, who should be directed to alternative therapies. Equally important are improvements in the matching between treatments and participants, which are dependent on the measurement of relevant pre-treatment variables. In the treatment of obesity and in many other pathologies and dependencies, the motivation to change has an important role both in the period of the weight loss and in the phase of the maintenance of the result. Therefore, if the patient is considered to be ready to lose weight, weight loss therapy should be initiated, if not, the immediate goal will be to prevent further weight gain and explore barriers to weight reduction. Many papers have been published regarding the measurement of the degree/level of motivation of the patient towards a specific treatment. Unfortunately, most of these questionnaires have been created and then applied to different areas; in particular they have been used before starting specific therapies for addiction. Unfortunately, a validated and easy-to-use questionnaire assessing at the meantime treatment motivation and readiness with adequate predictive capacity for weight loss actually is not available in most languages, so that empiric non-objective methods continue to be used.

A review of psychosocial pre-treatment predictors of weight control

Prompted by the large heterogeneity of individual results in obesity treatment, many studies have attempted to predict weight outcomes from information collected from participants before they start the programme. Identifying significant predictors of weight loss outcomes is central to improving treatments for obesity, as it could help professionals focus efforts on those most likely to benefit, suggest supplementary or alternative treatments for those less likely to succeed, and help in matching individuals to different treatments. To date, however, research efforts have resulted in weak predictive models with limited practical usefulness. The two primary goals of this article are to review the best individual-level psychosocial pre-treatment predictors of short- and long-term (1 year or more) weight loss and to identify research needs and propose directions for further work in this area. Results from original studies published since 1995 show that few previous weight loss attempts and an autonomous, self-motivated cognitive style are the best prospective predictors of successful weight management. In the more obese samples, higher initial body mass index (BMI) may also be correlated with larger absolute weight losses. Several variables, including binge eating, eating disinhibition and restraint, and depression/mood clearly do not predict treatment outcomes, when assessed before treatment. Importantly, for a considerable number of psychosocial constructs (e.g. eating self-efficacy, body image, self-esteem, outcome expectancies, weight-specific quality of life and several variables related to exercise), evidence is suggestive but inconsistent or too scant for an informed conclusion to be drawn. Results are discussed in the context of past and present conceptual and methodological limitations, and several future research directions are described.

Who will lose weight? A reexamination of predictors of weight loss in women

BACKGROUND: The purpose of this study was to analyze pretreatment predictors of short-term weight loss in Portuguese overweight and obese women involved in a weight management program. Behavioral and psychosocial predictors were selected a priori from previous results reported in American women who participated in a similar program. METHODS: Subjects were 140 healthy overweight/obese women (age, 38.3 +/- 5.9 y; BMI, 30.3 +/- 3.7 kg/m2) who participated in a 4-month lifestyle weight loss program consisting of group-based behavior therapy to improve diet and increase physical activity. At baseline, all women completed a comprehensive behavioral and psychosocial battery, in standardized conditions. RESULTS: Of all starting participants, 3.5% (5 subjects) did not finish the program. By treatment's end, more than half of all women had met the recomended weight loss goals, despite a large variability in individual results (range for weight loss = 19 kg). In bivariate and multivariate correlation/regression analysis fewer previous diets and weight outcome evaluations, and to a lesser extent self-motivation and body image were significant and independent predictors of weight reduction, before and after adjustment for baseline weight. A negative and slightly curvilinear relationship best described the association between outcome evaluations and weight change, revealing that persons with very accepting evaluations (that would accept or be happy with minimal weight change) lost the least amount of weight while positive but moderate evaluations of outcomes (i.e., neither low nor extremely demanding) were more predictive of success. Among those subjects who reported having initiated more than 3-4 diets in the year before the study, very few were found to be in the most successful group after treatment. Quality of life, self-esteem, and exercise variables did not predict outcomes. CONCLUSIONS: Several variables were confirmed as predictors of success in short-term weight loss and can be used in future hypothesis-testing studies and as a part of more evolved prediction models. Previous dieting, and pretreatment self-motivation and body image are associated with subsequent weight loss, in agreement with earlier findings in previous samples. Weight outcome evaluations appear to display a more complex relationship with treatment results and culture-specific factors may be useful in explaining this pattern of association.

Pretreatment predictors of attrition and successful weight management in women

OBJECTIVE

This study analyzed baseline behavioral and psychosocial differences between successful and nonsuccessful participants in a behavioral weight management program. Success was defined by commonly used health-related criteria (5% weight loss). Noncompletion was also used as a marker of a failed attempt at weight control.

SUBJECTS

A total of 158 healthy overweight and obese women (age, 48.0+/-4.5 y; BMI, 31.0+/-3.8 kg/m(2); body fat, 44.5+/-5.3%).

INTERVENTION

Subjects participated in a 16-week lifestyle weight loss program consisting of group-based behavior therapy to improve diet and increase physical activity, and were followed for 1 y after treatment.

METHODS

At baseline, all women completed a comprehensive behavioral and psychosocial battery assessing dieting/weight history, dietary intake and eating behaviors, exercise, self-efficacy, outcome evaluations, body image, and other variables considered relevant for weight management. Participants who maintained a weight loss of 5% or more at 16 months (or 10% or more of initial fat mass) were classified as successful. Nonsuccessful participants were those who dropped out and completers who had not lost weight at follow-up.

RESULTS

Of all participants, 30% (n=47) did not complete initial treatment and/or missed follow-up assessments (noncompleters). Noncompletion was independently associated with more previous weight loss attempts, poorer quality of life, more stringent weight outcome evaluations, and lower reported carbohydrate intake at baseline. In logistic regression, completion status was predicted correctly in 84% of all cases (chi(2)=45.5, P<0.001), using baseline information only. Additional predictors of attrition were initial weight, exercise minutes, fiber intake, binge eating, psychological health, and body image. A large variation in weight loss/maintenance results was observed (range: 37.2 kg for 16-month weight change). Independent baseline predictors of success at 16 months were more moderate weight outcome evaluations, lower level of previous dieting, higher exercise self-efficacy, and smaller waist-to-hip ratio. Success status at follow-up was predicted correctly in 74% of all starting cases (chi(2)=33.6, P<0.001).

CONCLUSION

Psychosocial and behavioral variables (eg, dieting history, dietary intake, outcome evaluations, exercise self-efficacy, and quality of life) may be useful as pretreatment predictors of success level and/or attrition in previously overweight and mildly obese women who volunteer for behavioral weight control programs. These factors can be used in developing readiness profiles for weight management, a potentially important tool to address the issue of low success/completion rates in the current management of obesity.

Weight locus of control and weight-related attitudes and behaviors in an overweight population

Rotter's [Psychol. Monogr. 80 (1966)] construct of internal-external control of reinforcement led to the conceptualization of locus of control as a personality construct that can be used to predict behavior. More specific measures of locus of control in particular behavioral domains have followed. In the present study, the Weight Locus of Control Scale (WLOC) was used to predict weight-related attitudes and behaviors of overweight individuals, as well as their responses to health education materials (HEM) on weight loss. The WLOC scores predicted responses to baseline weight-related measures such as etiology of obesity, confidence in weight loss behaviors, and behavioral intention. In addition, WLOC scores predicted participants' reactions to the HEM, as well as the actual number of weight loss ideas from the HEM that the participants tried by the 1-month follow-up assessment. The results are discussed in terms of the validity of the WLOC and implications for future development of effective HEM.

Influences on weight loss in type 2 diabetic patients: little long-term benefit from group behaviour therapy and exercise training

The aim of our study was to assess the long-term (24 months) efficacy of a comprehensive weight reduction programme as compared to that of a conventional programme. The Comprehensive Programme comprised, besides the Conventional Programme (diet counselling), behavioural modification and exercise training. The 2-year follow-up period was completed by 53 patients (19M/34F; 88.3%). The differences (95% confidence intervals; CI) between the change in body weight of patients in the Comprehensive Programme compared to the Conventional Programme after 6 and 24 months of treatment were -2.2 (-4.0, -0.3) kg, p = 0.03 and -1.3 (-3.3, 0.7) kg, p = 0.21, respectively. In comparison to the Conventional Programme, the Comprehensive Programme resulted in a greater decrease (95% CI) of HbA1c after 6 months: -0.8 (-1.2, -0.2)%, p = 0.01, but not after 2 years: -0.4 (-1.0, 0.1)%, p = 0.12. The effects on blood pressure and serum lipids of the Comprehensive Programme and the Conventional Programme were comparable. Changes in body weight at 6 months correlated well with changes in HbA1c, fasting plasma insulin, and blood pressure, whereas at 24 months no such correlation was found with HbA1c. Pretreatment variates that were associated with the greatest 2-year weight loss were a high HbA1c value, a low energy per cent carbohydrate intake and a low percentage of obese subjects within the family. In conclusion, the long-term outcome of the Comprehensive Programme was not different from that of the Conventional Programme. The achieved body weight reduction was associated with a sustained fall in blood pressure, but with only a transient beneficial effect on the glycaemic control in the Type 2 diabetic patient.

Locus of control orientation among obese adults in outpatient treatment for obesity

We studied locus of control (LOC) in samples of obese and nonobese subjects. We administered Rotter's (1966) I-E Scale to 106 obese adults in outpatient treatment for obesity and to 99 nonobese controls. The obese subjects were significantly more internally oriented than the control group. These findings challenge currently held assumptions on the directionality of LOC in obese groups. The results contradict the consensus among researchers that obese individuals have an external LOC orientation. The finding that internal LOC is associated with the obese condition may be a useful predictor variable influencing obesity treatment, approaches, and outcome.

Three-year follow-up of Pawtucket Heart Health's community-based weight loss programs

PURPOSE

The purpose of the study was to evaluate the effectiveness of a community-based weight loss program.

DESIGN

A questionnaire was administered by telephone to subjects one to three years following participation in a weight loss program.

SETTING

The study took place in Pawtucket, Rhode Island. The Pawtucket Heart Health Program is part of this setting.

SUBJECTS

A stratified sample of 400 subjects was randomly selected from 2,186 people who participated in weight loss programs between 1985 and 1987. A total of 285 subjects completed the questionnaire; 229 subjects provided sufficient information to be included in the study.

INTERVENTION

The subjects participated in community-based and worksite-based weight loss programs.

MEASURES

Self-reported heights and weights before and after intervention and demographic data were collected. Desirable body weight and Garrow's health risk classifications were calculated.

RESULTS

Overall, there was a 3.2% reduction in body weight between time of entrance into weight loss programs and time of interview. Eighty percent of the participants lost weight in the program; mean weight loss was 11 pounds. At time of follow-up interview one to three years later, 65% of subjects weighed less than at entrance into the community programs; on average, subjects weighed six pounds less. Sixty-nine percent of the sample was above 20% desirable body weight at entrance and 26% of this group lost enough weight to lower their health risk category.

CONCLUSIONS

Weight loss in this community-based program compares favorably with those reported by more intense and expensive clinic-bound programs.(ABSTRACT TRUNCATED AT 250 WORDS)

Control orientation as a personality dimension among alcoholic and obese adult men undergoing addictions treatment

Rotter's (1966) I-E Locus of Control Scale was administered to 18 men in residential treatment for alcoholism and 13 men in intensive outpatient treatment for obesity. The obese sample scored significantly higher in internal locus of control, whereas the alcoholic sample was comparatively external in control orientation. These findings contradict currently held assumptions on the directionality of control orientation among both alcoholic and obese adults and suggest that internally oriented obese adults may feel that they have little control over their weight and eating behavior but more control over other aspects of their lives. In contrast, externally oriented alcoholics appear to be aware of their inability to control their drinking and their limited control over many factors influencing their lives. Implications for treatment are also discussed.

Differences in locus of control between obese adult and adolescent females undergoing weight reduction

Rotter's (1966) Internal-External (I-E) Scale was administered to 65 adult and adolescent females in two outpatient obesity treatment programs. The adults were significantly higher in internal locus of control (LOC) and the adolescents higher in external LOC. These differences suggest that although the adults felt limited control over their weight and eating behavior, this did not reflect a lack of perceived control over other factors in their lives. In contrast, the adolescents appeared to feel that they had limited control over an array of factors in their lives.

Distressed binge eaters as a distinct subgroup among obese individuals

This study was conducted to examine the degree to which binge eating and psychological distress among obese adults are associated with a variety of behavioral patterns and competencies that could substantially affect weight control. Subjects were 167 obese people who sought help in a long-term cognitive behavioral treatment program. Subjects were divided into three groups depending on their level of psychological distress and severity of binge eating. Subjects were also assessed on coping style, subjective distress, weight history, and exercising and eating patterns. Results demonstrated substantial differences between those reporting relatively few problems with binge eating or psychological distress as opposed to those with noteworthy problems in both. The presence of either severe binge eating or psychological distress was associated with problems in regulating food-related behavior and, more generally, to problematic coping styles. These findings support the importance of in-depth assessment when treating obesity, more intensive treatment for some subgroupings, and long-term studies that incorporate comprehensive pretreatment process measure of eating style and psychological distress.

Body weight attributions and eating self-efficacy in adolescence

In an attempt to find an optimum age during adolescence to target weight control programs successfully, 189 adolescents were surveyed using measures of eating self-efficacy and body-weight attributions. The sensitivity of the attribution measures was assessed in a pilot study using 100 adolescents. The major experiment indicated higher levels of eating control at 12 and 13 years of age, decreasing with age. However, the locus of control measure indicated an increase in internal attributions with age. It is argued that this paradox between degree of control subjects reported over their eating and the degree subjects believed their body weight to be controlled internally may have important clinical implications and should be investigated further.

Attributions for previous failures and subsequent outcomes in a weight reduction program

This prospective study examines the effects of causal attributions given to previous weight control failures on subsequent success in controlling weight. Adult participants enrolled in a weight control program were screened to identify those who had made previous weight reduction attempts through a formal program. Once identified, subjects (n = 158) were asked to make causal attributions for their previous failures. Subjects were then followed through the 15-week program to determine their degree of success. Subjects who attributed the cause of previous failures to stable, immutable conditions were more likely to have low expectations of success. Low success expectancies, in turn, were associated with lack of goal attainment through the program. The number of previous failures in formal weight control programs was associated with a perception of the respondents that previous failures had stable causes. Neither the number of former failures nor the attributions of their causes were directly related to goal attainment. Practice implications of the results are discussed.

Restructuring: an emerging theory on the process of losing weight

A qualitative research design (grounded theory) was used to analyse the experiences of dieters attending a weight loss programme. Two hundred hours of observations at a nationally known weight reduction centre, a review of selected documents from the organization and multiple in-depth interviews with 13 informants were the data sources for this study. Data generation took place over a 21-month period. A substantive theory of restructuring identified three stages in the process of losing weight. These stages and key elements of the weight loss process are presented.

Self-efficacy and self-motivation as predictors of weight loss

The present study was attempted to determine whether self-efficacy and self-motivation would predict outcome in an intensive weight loss program. The subjects included 52 males and 95 females who were at least fifty pounds overweight (mean age = 43 years). The data were analyzed through multiple regression on three separate dependent variables: actual weight loss, adjusted weight loss and percentage of sessions attended. Outcome was predicted based on the following variables: self-efficacy (as measured by confidence estimates and outcome expectancies) and self-motivation (as measured by the Self-Motivation Inventory). The predictors accounted for 32.2% (p less than .01) of the variance in actual weight loss, 8.5% (p less than .01) of the variance in adjusted weight loss and none of the variance in percentage of sessions attended. Self-motivation did not correlate significantly with either actual or adjusted weight loss, while self-efficacy measures did. However, the correlation of the two self-efficacy measures (r = -.07, p greater than .05) suggests that these variables do not constitute a unitary construct and should be conceptualized as independent predictors. These findings suggest that confidence estimates and outcome expectancies are useful predictors of weight loss.

An evaluation of self-instructional training in the treatment of obesity

An experimental evaluation of a cognitive self-instructional procedure for increasing self-control of eating was carried out in a weight reduction programme for obese women. All subjects received a 'core', 16 week long treatment programme of nutritional advice and encouragement provided by five group meetings and one individual session. Subjects were randomly assigned to receive only the core programme, or the core programme plus seven individual sessions of one of three types of treatment. Thus there were four treatment conditions: (a) Cognitive Rehearsal (Self-instructional training attempting to teach subjects to resist temptation through the self-directing power of inner speech), (b) Insight Control (teaching subjects to become aware of, but not to change, unhelpful cognitions), (c) Individual Contact Control (encouragement and nondirective discussion of dieting) and (d) Group Contact Control (core programme only). Of the 94 subjects entering the programme 74 completed the 16 weeks of treatment and 69 were followed up a year later. There were no significant differences between treatments in obesity reduction either at the end of treatment or at followup. There were significant reductions in anxiety and depression and in initially unrealistically high outcome expectations. Initial weight loss, an apparently important variable, predicted subsequent losses.

Participant characteristics as predictors of attrition in worksite weight loss

Attrition is a significant problem in worksite weight loss interventions, and differences in participants' motivational levels have been hypothesized to account for this high attrition rate. The present study examined characteristics of participants who completed a worksite weight loss program compared to those who dropped out, using a step-wise discriminant function analysis. The results indicate that a combination of motivational characteristics, expectations, and change in weight just prior to treatment significantly discriminated drop-outs from completers. The results of this investigation are discussed with respect to implications for developing cost-effective worksite treatment protocols and directions for future research.

Eating behavior, personality traits and body mass in women

In an exploratory study in women, the relationships between scales of emotional eating, external eating, and restrained eating, and body mass index (BMI = weight/height2) were studied, as well as the interrelationships between these three eating behavior components. In addition, the relationships between the three eating behavior scales and 19 personality scales were examined. Finally, differences between obese and latent obese women with respect to eating behavior and personality were investigated. Significant relationships were found between BMI and emotional eating, and between BMI and external eating/perceived hunger, but not between BMI and Restrained Eating. Also, restrained eating was found not to be related to the other two eating behavior components. Of the three eating behavior components, emotional eating was shown to have the clearest relationships with a number of personality traits. No difference was observed between the eating behavior of latent obese and obese women, but these groups differed as to a number of personality traits. These results are discussed in terms of consequences for prevalent theories on restrained, external, and emotional eating.

Variables related to continuance in a behavioral weight loss program

This study compared nonoutcome characteristics of completers and dropouts in a behavioral weight loss program. The significant relationships between several personality dimensions and continuance were discussed. It was proposed that the unusual finding of personality differences was made possible by distinguishing early from late dropouts.

A descriptive analysis of men and women who have lost significant weight and are highly successful at maintaining the loss

Forty-one women and 13 men who have lost at least 20% of their body weight and still maintain the loss after at least two years responded to newspaper and television publicity and were interviewed. Significant sex differences were found in strategies for weight loss and subsequent maintenance. In addition to increased exercise, nutritional sophistication, and self-monitoring in both sexes, the majority of female subjects assumed responsibility for their need to lose weight, developed their own diets, exercise, and maintenance plans, and have become more involved in business and other activities outside the home.

Experienced control and participation in treatment of obesity

Results of three studies are presented which explore the relation of experienced control to participation in treatment for obesity. Subjects in all studies were adult females participating in an outpatient, behaviorally-oriented obesity program. Experienced control was measured using the Experienced Control Scale (Tiffany, 1967). Study 1 was a naturally occurring experiment which compared two groups ( ns = 7 and 8) that differed in extent of self-directed efforts to begin treatment. Study 2 compared 32 persons who completed the program and 18 persons who did not complete it. High levels of experienced control over internal forces were associated with increased efforts to initiate treatment and with completion of treatment. Study 3 assessed the temporal stability of the Experienced Control Scale with obese females tested at the beginning and end of the 12-wk. treatment program. Test-retest reliability coefficients were .64 ( p < .01) for the internal control subscale and .29 ( P < .10) for the external control subscale.