Behavior therapy for obesity: Booster sessions and long-term maintenance of weight loss

Following 8 weekly sessions of group behavioral self-control treatment, 75 obese women were assigned to one of five different maintenance conditions: (a) structured behavioral booster sessions held every two weeks; (b) structured behavioral booster sessions held every month; (c) unstructured nonspecific booster sessions held every two weeks; (d) unstructured nonspecific booster sessions held every month; and (e) a control group that received no booster sessions. Follow-ups were conducted at 3, 6, 9 and 12 month intervals. The study was completed in two replications. Results failed to show a significant effect of either booster session content or frequency. All groups continued to lose weight during the first three months of follow-up. Thereafter subjects in Replication 1 showed significant increases in weight over the next 9 months, whereas subjects in Replication 2 maintained their treatment-produced weight loss. The data do not support the view that booster sessions facilitate maintenance.     

The efficacy of a short version of a cognitive-behavioral treatment followed by booster sessions for binge eating disorder

This waitlist-controlled study evaluated the efficacy of a short version of a group CBT for BED followed by booster sessions after the active treatment phase. Thirty-six females with BED were randomly assigned to CBT (eight weekly sessions during active treatment plus five booster sessions during follow-up) or a waitlist condition. At the end of the active treatment, binge eating was significantly reduced relative to waitlist. Furthermore, at 12-month follow-up short-term CBT produced significant improvements in binge eating symptoms relative to baseline. Findings suggest that the short-term CBT followed by booster sessions may provide a valuable treatment option for patients with BED.     

An animal model of excessive eating: schedule-induced hyperphagia in food-satiated rats.

Nineteen rats were maintained throughout the experiment on ad libitum wet mash and water and were trained to press a lever on fixed-interval or fixed-ratio schedules of reinforcement with electrical brain stimulation. Fourteen rats ate at least 150% more mash during intermittent reinforcement sessions than during baseline, massed reinforcement control, and/or extinction sessions. In a 3-hr session, 11 of those 14 consumed more than 22 g of wet mash (13 g dry weight), the equivalent of nearly half an animal's daily food intake. In subsequent control sessions, the electrodes did not support stimulus-bound eating despite attempts to make stimulation parameters optimal. These results indicate that the eating was schedule induced or adjunctive, and suggest that the procedure may provide an animal model of excessive nonregulatory eating that contributes to obesity in humans.     

Challenging body weight: evidence from a community-based intervention on weight,behaviour and motivation

The objective of this study was to examine the effectiveness of a 12 week weight loss intervention within a commercial fitness centre on body weight, moderate to vigorous physical activity (MVPA), dietary intake, and behavioural regulations for exercise and healthy eating. Using a quasi-experimental design, the intervention group received weekly coaching sessions and bi-weekly seminars designed to increase MVPA and improve dietary intake. Outcome variables were assessed at three time points over a six month period. Results showed a significant interaction for body weight (p = .04) and dietary changes (p < .05) following the weight loss challenge but were not maintained across the six month period. Changes in behavioural regulations favoured the intervention condition. Results imply that a 12 week weight loss challenge within a commercial fitness centre may be effective at prompting short-term weight loss and support the internalization of behavioural regulations specific to healthy eating and exercise.     

An Open Trial Examining Dialectical Behavior Therapy Skills and Behavioral Weight Loss for Adults With Emotional Eating and Overweight/Obesity

Third-wave cognitive behavioral interventions for weight loss have shown promise. However, sparse data exists on the use of dialectical behavior therapy for weight loss. Adapted dialectical behavior therapy skills programs may be especially well suited for adults who engage in emotional eating and are seeking weight loss. Dialectical behavior therapy is skills-based, shares theoretical links to emotional eating, and is effective in treating binge eating. The current study examined the feasibility, acceptability, and preliminary efficacy of Live FREE: FReedom from Emotional Eating, a 16-session group-based intervention. A total of 87 individuals expressed interest in the program, and 39 adults with overweight/obesity (BMI ≥25) and elevated self-reported emotional eating were enrolled. Live FREE targeted emotional eating in the initial sessions 1–9, and sessions 10–16 focused primarily on behavioral weight loss skills while continuing to reinforce emotion regulation training. Assessments were administered at baseline, posttreatment, and 6-month follow up. Enrolled participants were primarily female (97.4%) and Caucasian (91.7%). Treatment retention was strong with participants attending an average of 14.3 sessions and 89.7% of participants completing the intervention. On average, participants lost 3.00 kg at posttreatment, which was maintained at follow-up. Intent-to-treat analyses showed improvements in key outcome variables (self-reported emotional eating, BMI, emotion regulation) over the course of the intervention. Combining dialectical behavior therapy skills with conventional behavioral weight loss techniques may be an effective intervention for adults with overweight/obesity who report elevated emotional eating.     

Oral self-administration of pentobarbital by rhesus monkeys: maintenance of behavior by different concurrently available volumes of drug solution.

For 4 rhesus monkeys, mouth-contact responses with either of two brass spouts were reinforced according to fixed-ratio schedules by 0.65-mL liquid deliveries during daily 3-hr sessions. Three experiments were conducted. In each experiment, independent fixed-ratio schedules were concurrently in effect at the two spouts. Following completion of each fixed ratio on a spout, a specified number of liquid deliveries were available from that spout under a continuous-reinforcement schedule. The number of such deliveries available at each spout was manipulated independently. In Experiment 1, a 1-mg/mL pentobarbital solution was simultaneously available with water (the drug vehicle) under concurrent fixed-ratio schedules of 32 responses for 3 subjects and 64 responses for the remaining subject. The number (N) of liquid deliveries that were available after completion of each fixed ratio was varied in the following order: 8, 4, 2, 1, and 8 (retest). For each subject at each condition, drug maintained more responding than water. The number of drug deliveries obtained per session was directly related to the amount of drug available per fixed ratio (i.e., to N), whereas the number of fixed ratios completed per session generally was inversely related to the value of N. In Experiment 2, fixed-ratio size was the same for each subject as in Experiment 1, but deliveries of a 1-mg/mL pentobarbital solution were available at both spouts. The number of drug deliveries available under one fixed-ratio schedule (Ns, the "standard" reinforcer amount) was held at eight, and the number of drug deliveries available under the second schedule (Nc, the "comparison" reinforcer amount) was changed across blocks of six sessions of stable responding in the following order: 1, 2, 4, 8, 4, 2, and 1. The identical series of comparison reinforcer amounts (Nc) was then tested twice more, but with the standard reinforcer (Ns) held first at four and then at two deliveries. Across the three choice series, reinforcing effects were directly related to reinforcer magnitude. In Experiment 3, deliveries of a 1-mg/mL pentobarbital solution again were available at both spouts. However, the two reinforcer amounts were held constant at N = 8 deliveries under one schedule and N = 4 deliveries under the second schedule, and fixed-ratio size was systematically varied. Across the range of fixed-ratio sizes from low to high, the degree to which behavior was better maintained by the larger of the two drug quantities was an inverted U-shaped function of fixed-ratio size.(ABSTRACT TRUNCATED AT 400 WORDS)     

Effects of search cost on foraging and feeding: a three-component chain analysis

An experiment determined whether pigeons minimize number of key pecks per food delivery and maintain their baseline intake of food while key pecking on a three-component chain schedule. Pigeons at either 80% or 100% body weight obtained all their food during baseline and contingency sessions. During baseline sessions, pecks on the left and center keys had no consequences; each peck on the right key activated the feeder. During contingency sessions, pigeons key pecked on a three-component chain schedule simulating components of a foraging chain. In the search component either 3, 9 or 15 key pecks (varied parametrically across blocks of sessions) on the left key produced a stimulus on the middle key, indicating an encounter with either the low-cost prey (3 key pecks) or an equally probable high-cost prey (21 key pecks). In the procurement component the pigeon pecked either: (a) the left key once, thus returning to the search component, or (b) the middle key either 3 or 21 times, which activated the right response key. In the handling component one peck on the right key operated the feeder. The pigeons always procured the low-cost prey and minimized the number of key pecks per hopper by procuring the high-cost prey when the search-cost ratio was high (15 key pecks) but not when it was low (3 key pecks). All pigeons maintained their baselines of eating during contingency sessions by key pecking more frequently and eating more efficiently. The 80% body-weight birds produced higher overall rates of key pecking and eating. These results have implications for ecological theories of optimal foraging and for psychological theories of learned performance.     

Motivational influences on performance maintained by food reinforcement

In Study 1, we examined the independent effects of reinforcer consumption during sessions and meal consumption prior to sessions on performance maintained by food reinforcement. Nine individuals with developmental disabilities participated. On alternate days, a preferred edible item was delivered during (a) seven sessions conducted before lunch (repeated-reinforcement condition) versus (b) one session each conducted before and after lunch (pre- and postmeal conditions). Results for 7 of 9 participants showed decreased response rates across sessions in the repeated-reinforcement condition; results for 3 of 9 participants showed decreased rates during postmeal relative to premeal conditions. Two participants who did not show a decrement in responding during either comparison participated in Study 2, in which reinforcer consumption during sessions, combined with meal consumption prior to sessions, also had no effect on their performance. In Study 3, we determined whether (a) choice of reinforcers, (b) increased break time between sessions, (c) varied reinforcers, or (d) intermittent reinforcement schedules mitigated the satiation effects observed for the 7 participants in Study 1. Presession choice of reinforcers resulted in maintained performance for 2 of 6 participants exposed to this condition. Varied reinforcement resulted in maintained performance for only 1 of 5 participants exposed to this condition. Neither the increased break between sessions nor the intermittent reinforcement schedule was effective in maintaining performance for the participants who were exposed to these conditions.     

Correlates of unhealthy weight-control behaviors among adolescents: implications for prevention programs.

This study aimed to identify correlates of unhealthy weight-control behaviors in adolescents to guide the development of programs aimed at the primary prevention of disordered eating. A model explaining unhealthy weight-control behaviors was tested among 4,746 adolescents using structural equation modeling. Models fit the data well and explained 76% of the variance in unhealthy weight-control behaviors among girls and 63% among boys. Weight-body concerns were a strong correlate of unhealthy weight-control behaviors in both girls and boys. Models also emphasized the importance of weight-specific social norms within the adolescent's proximal environment. Findings suggest the importance of addressing weight-body concerns within prevention programs and extending interventions beyond classroom settings to ensure changes in weight-related norms among peer groups and family members.     

Disordered eating behaviors and body image in a longitudinal pilot study of adolescent girls: What happens 2 years later?

We assessed the prospective association of risk factors for eating and body image disturbances after a 2-year follow-up in a community sample of Spanish adolescent girls. The participants included 128 Spanish girls aged 12–14, who took part in a 28-month prospective study. Aspects assessed were eating attitudes (Eating Attitudes Test), influence of the body shape model (questionnaire on influences of the aesthetic body shape model), extreme weight-control behaviors (Eating Disorder Examination-Questionnaire), body image (Body Image Questionnaire) and Body Mass Index (BMI). BMI, extreme weight-control behaviors and body image problems emerged as potential predictors of an increase in eating disturbances. An increased influence of the thinness model was significantly associated with reduced body satisfaction and body image problems. Preventive programs are needed to contribute reducing the impact of sociocultural influences with regard to thinness, the use of extreme weight-control behaviors and overweight in adolescents.     

Maintenance of weight loss after obesity treatment: is continuous support necessary?

OBJECTIVE: This study examined outcome differences of 109 obese subjects, who participated in a 10-week cognitive-behavioral inpatient treatment followed by either a weight maintenance program or a follow-up period without professional support. METHODS: Self-rated weight loss, eating behaviors, and general psychopathology were assessed several months before treatment, when subjects were admitted, at discharge, and at the 6-, 12-, and 18-month follow-ups. Structured interviews for mental disorders and eating pathology were conducted additionally. RESULTS: The mean weight of the sample at baseline was 127 kg. Weight loss of the total sample amounted to 8.0 kg (6.3%) and was completely maintained during the follow-up period. Significant reductions of eating and general psychopathology were observed at the 18-month follow-up. The outcome in the maintenance condition did not significantly differ from the outcome in the control condition. CONCLUSIONS: Weight regain after obesity treatment is not inevitable, but continuous patient-therapist contacts do not distinctly improve treatment effects.     

The impact of attitudinal ambivalence on weight loss decisions: Consequences and mitigating factors

This research takes a new look at individuals' attitudes and intentions towards losing weight. Study 1 examines the relationship among those interested in losing weight and individual self‐evaluative ambivalence on attitude towards trying to achieve a weight loss goal and the intentions to achieve the weight loss goal. For Study 2, a between‐subjects experimental design, where attitudinal ambivalence and prior outcome feedback were manipulated and self‐efficacy was measured, is conducted to examine attitude towards eating healthier and intention to change eating behaviours. Findings across the two studies show that attitudinal ambivalence about the self and the individual's abilities and motivation to change the health behaviour produces a negative relationship between health‐related attitudes and intentions. We provide implications of how self‐efficacy and the provision of outcome feedback can alleviate the negative effect and improve the individuals' intentions to try to achieve a weight loss goal. Copyright © 2014 John Wiley & Sons, Ltd.     

Predictors of attrition and weight loss success: Results from a randomized controlled trial

Attrition is a common problem in weight loss trials. The present analysis examined several baseline and early-treatment process variables, as predictors of attrition and outcome in a clinical trial that combined pharmacotherapy and behavior therapy for weight loss. Participants were 224 obese adults who were treated with sibutramine alone, lifestyle modification alone, combined therapy, or sibutramine plus brief lifestyle modification. Predictors included baseline characteristics (e.g., demographic, weight-related, psychological, and consumption-related variables), plus attendance, adherence, and weight loss in the early weeks of treatment. Outcomes were attrition and weight loss success (i.e., ≥5% reduction in body weight) at 1 year. Multivariable models, adjusting for other relevant variables, found that younger age and greater baseline depressive symptoms were related to increased odds of attrition (ps ≤ 0.003). Greater early weight loss marginally reduced the odds of attrition (p = 0.06). Predictors of weight loss success at 1 year were Caucasian ethnicity (p = 0.04), lower baseline depressive symptoms (p = 0.04), and weight loss during the first 3 weeks of treatment (p < 0.001). Thus, depressive symptoms at baseline were a significant predictor of both attrition and weight loss success. As a process variable, early weight loss appears to have more predictive value than early attendance at treatment sessions or early adherence.     

No counterregulation after breaking the external restraint of children.

At the present, it is unknown how restraint and binge eating/counterregulation are exactly related. Earlier studies on this relationship suffer from two main shortcomings: the studies are all correlational in nature or could not rule out the contribution of confounding variables such as weight loss. The present study investigated whether a break of restraint is a sufficient condition for the occurrence of counterregulation by studying a restrained sample which is not liable to dieting practices and weight loss. The externally imposed restraint on children with regard to eating sweets was broken. However, after breaking their external restraint the children did not counterregulate. It is discussed whether restraint of food intake is really as important for binge eating as it is claimed to be or whether it is merely a consequence or an epiphenomenon of binge eating.     

Effects Of Histories Of Differential Reinforcement Of Response Rate On Variable-interval Responding

Three pigeons were exposed first to multiple differential-reinforcement-of-high-rate and differential-reinforcement-of-low-rate schedules that were correlated with green and red keys, respectively, and then were shifted to a variable-interval schedule arranged on a white key. In subsequent test sessions, the variable-interval schedule continued to operate, but green and red keys replaced the white key in alternate sessions. In Part 1 of the experiment, the variable-interval schedule correlated with the white key was introduced immediately after the multiple-schedule condition, and the test condition began 15 days later. This sequence was repeated twice, with a reversal of the correlation of the key colors with the components of the multiple schedule at the start of each new cycle. Part 2 added a 6-month break between the multiple-schedule history and the white-key variable-interval schedule followed by test sessions. The procedure was then repeated with a reversal of the correlation between key colors and multiple-schedule components. In the test sessions of Part 1, all pigeons consistently responded faster in the presence of the key color most recently correlated with the differential-reinforcement-of-high-rate contingency than during the color most recently correlated with the differential-reinforcement-of-low-rate contingency. Similar but smaller effects were observed in Part 2. The effects of the reversals in these two parts of the experiment showed that only the most recent contingency exerted an influence on subsequent responding. The data suggest that this effect of the most recent history continues to operate on behavior under current contingencies even after a long lapse of time.     

The Role of Trait Self-Objectification in Smoking among College Women

Self-objectification, which is the internalization of an observer’s perspective of the self, has been related to restrained and disordered eating patterns and depression. Because disordered eating and depression are known co-factors for smoking, we tested the possible involvement of trait self-objectification in the relationship between these mental health dimensions and smoking in a sample of 130 college women smokers and non-smokers. As hypothesized, we found that trait self-objectification mediated the relationship between smoking status and dieting and disordered eating behaviors. There were no significant differences in depression between smokers and non-smokers, which limited further exploration of the relationship. Implications for trait self-objectification as relevant to women’s weight-control smoking and the relevance of self-objectification to other health behaviors are discussed.     

Diversity and substitutability of adjunctive activities under fixed-interval schedules of food reinforcement

Six rats received food contingent on pressing a lever on fixed-ratio 1, fixed-interval 30-second, and fixed-interval 60-second schedules, with concurrent access to a drinking spout, a running wheel, and a block of wood. Drinking, running, and chewing were monitored automatically, and these and other activities were observed directly during selected sessions. Because all sessions ended after delivery of 60 pellets, total time available for activities other than eating increased over the three schedules. Time spent contacting the lever and visiting the food tray increased in proportion to total available time, whereas the time spent in other activities changed in a complex manner such that drinking was the dominant adjunctive behavior in the 30-second condition, and running or chewing the dominant adjunctive behavior in five of six rats in the 60-second condition. General activity and grooming also occupied significant amounts of time. In a subsequent part of the experiment, running and chewing were prevented, and the majority of other activities, especially drinking and grooming, increased. The results show that (a) FI schedules of food reinforcement are accompanied by a wide variety of adjunctive activities; (b) the preferred activity differs according to the schedule duration; and (c) the extent to which activities substitute for one another is limited by the tendency for different activities to occupy different parts of the interreinforcement interval.     

Assessment of emotional reactivity produced by exposure to virtual environments in patients with eating disorders.

The aim of this study was to assess the usefulness of virtual environments representing situations that are emotionally significant to subjects with eating disorders (ED). These environments may be applied with both evaluative and therapeutic aims and in simulation procedures to carry out a range of experimental studies. This paper is part of a wider research project analyzing the influence of the situation to which subjects are exposed on their performance on body image estimation tasks. Thirty female patients with eating disorders were exposed to six virtual environments: a living-room (neutral situation), a kitchen with high-calorie food, a kitchen with low-calorie food, a restaurant with high-calorie food, a restaurant with low-calorie food, and a swimming-pool. After exposure to each environment the STAI-S (a measurement of state anxiety) and the CDB (a measurement of depression) were administered to all subjects. The results show that virtual reality instruments are particularly useful for simulating everyday situations that may provoke emotional reactions such as anxiety and depression, in patients with ED. Virtual environments in which subjects are obliged to ingest high-calorie food provoke the highest levels of state anxiety and depression.     

The effects of chlorpromazine and imipramine on rate and stimulus control of matching to sample.

Pigeons were trained to perform simultaneous, two-color matching to sample under a multiple fixed-ratio fixed-interval schedule of food presentation. The sequence terminating with a peck on the matching key (a "match") was treated as a unit, analogous to a single key peck in conventional schedules. Except for intermittent reinforcement of matches, no consequent stimulus distinguished matches from mismatches (sequences terminating with pecks on the nonmatching key). The pattern of matches during nondrug sessions resembled that of simpler operants maintained by similar schedules. Matches increased in rate toward the end of both components; mismatch rates increased more slowly. Imipramine increased the rate of mismatches, disrupted schedule patterning, and lowered accuracy in a dose-dependent fashion. Chlorpromazine lowered the overall rate of matches but affected schedule patterns and accuracy less than imipramine. The types of errors during drug sessions were not systematically related to the types of errors that appeared during nondrug sessions. Stimulus control was evaluated for each of the four possible color configurations and was found to be by the entire configuration of colors, not simply by the color of the sample.     

Contracting,equal, and expanding learning schedules: The optimal distribution of learning sessions depends on retention interval

In laboratory and applied learning experiments, researchers have extensively investigated the optimal distribution of two learning sessions (i.e., initial learning and one relearning session) for the learning of verbatim materials. However, research has not yet provided a satisfying and conclusive answer to the optimal scheduling of three learning sessions (i.e., initial learning and two relearning sessions) across educationally relevant time intervals. Should the to-be-learned material be repeated at decreasing intervals (contracting schedule), constant intervals (equal schedule), or increasing intervals (expanding schedule) between learning sessions? Different theories and memory models (e.g., study-phase retrieval theory, contextual variability theory, ACT-R, and the Multiscale Context Model) make distinct predictions about the optimal learning schedule. We discuss the extant theories and derive clear predictions from each of them. To test these predictions empirically, we conducted an experiment in which participants studied and restudied paired associates with a contracting, equal, or expanding learning schedule. Memory performance was assessed immediately, 1 day, 7 days, or 35 days later with free- and cued-recall tests. Our results revealed that the optimal learning schedule is conditional on the length of the retention interval: A contracting learning schedule was beneficial for retention intervals up to 7 days, but both equal and expanding learning schedules were better for a long retention interval of 35 days. Our findings can be accommodated best by the contextual variability theory and indicate that revisions are needed to existing memory models. Our results are practically relevant, and their implications for real-world learning are discussed.