Background/ObjectivesControlling food portion sizes can help reduce energy intake, but the effect of different portion-control methods on weight management is not known. In a one-year randomized trial, we tested whether the efficacy of a behavioral weight-loss program was improved by incorporating either of two portion-control strategies instead of standard advice about eating less.Subjects/MethodsThe Portion-Control Strategies Trial included 186 women with obesity (81%) or overweight (19%). Participants were randomly assigned to one of three equally intensive behavioral programs consisting of 19 individual sessions over 12 months. The Standard Advice Group was instructed to eat less food while making healthy choices, the Portion Selection Group was instructed to choose portions based on energy density using tools such as food scales, and the Pre-portioned Foods Group was instructed to structure meals around pre-portioned foods such as single-serving main dishes, for which some vouchers were provided. In an intention-to-treat analysis, a mixed-effects model compared weight loss trajectories across 23 measurements; at Month 12, weight was measured for 151 participants (81%).ResultsThe trajectories showed that the Pre-portioned Foods Group initially lost weight at a greater rate than the other two groups (P=0.021), but subsequently regained weight at a greater rate (P=0.0005). As a result, weight loss did not differ significantly across groups at Month 6 (mean±SE 5.2±0.4 kg) or Month 12 (4.5±0.5 kg). After one year, measured weight loss averaged 6% of baseline weight. The frequency of using portion-control strategies initially differed across groups, then declined over time and converged at Months 6 and 12.ConclusionsIncorporating instruction on portion-control strategies within a one-year behavioral program did not lead to greater weight loss than standard advice. Using pre-portioned foods enhanced early weight loss, but this was not sustained over time. Long-term maintenance of behavioral strategies to manage portions remains a challenge.

With modern technological advances, we often find ourselves dividing our attention between multiple tasks. While this may seem a productive way to live, our attentional capacity is limited, and this yields costs in one or more of the many tasks that we try to do. Some people believe that they are immune to the costs of multitasking and commonly engage in potentially dangerous behavior, such as driving while talking on the phone. But are some groups of individuals indeed immune to dual-task costs? This study examines whether avid action videogame players, who have been shown to have heightened attentional capacities, are particularly adept multitaskers. Participants completed three visually demanding experimental paradigms (a driving videogame, a multiple-object-tracking task, and a visual search), with and without answering unrelated questions via a speakerphone (i.e., with and without a dual-task component). All of the participants, videogame players and nonvideogame players alike, performed worse while engaging in the additional dual task for all three paradigms. This suggests that extensive videogame experience may not offer immunity from dual-task costs.

Objective During a one-year weight loss trial, we compared the Three-Factor Eating Questionnaire (TFEQ), a valid 51-item measure of restraint, disinhibition, and hunger subscales, with the newer 16-item Weight-Related Eating Questionnaire (WREQ) measuring routine and compensatory restraint and external and emotional eating. Methods Both questionnaires were administered to women with overweight or obesity (n = 186, mean±SD, age 50±10.6 y, BMI 34±4.2 kg/m2) at five time points. Completion rates were 100% at baseline and Month 1, 94% at Month 3, 83% at Month 6, and 76% at Month 12. Confirmatory factor analysis was conducted on baseline WREQ data and correlations were calculated between TFEQ and WREQ subscales. Multilevel models evaluated the relationship between each subscale and weight change over time. Results Factor analysis revealed a WREQ structure consistent with previous research, and corresponding subscales on the TFEQ and WREQ were correlated. Lower baseline TFEQ restraint predicted greater weight loss. Across five administrations, TFEQ and WREQ restraint scores were positively related to weight loss (p<0.01) and TFEQ disinhibition and WREQ external and emotional eating scores were negatively related (p<0.001). Thus, with one baseline administration, only TFEQ restraint was significantly related to weight change, but multiple administrations showed relationships between all TFEQ and WREQ subscales and weight change. Conclusions The WREQ offers a shorter alternative to the TFEQ when repeatedly assessing eating behaviors related to weight change.

SummaryObjectiveThe Diet Satisfaction Questionnaire was developed to fill the need for a validated measure to evaluate satisfaction with weight‐management diets. This paper further develops the questionnaire, examining the factor structure of the original questionnaire, cross‐validating a revised version in a second sample and relating diet satisfaction to weight loss during a 1‐year trial.MethodsThe 45‐item Diet Satisfaction Questionnaire (DSat‐45) uses seven scales to assess characteristics that influence diet satisfaction: Healthy Lifestyle, Convenience, Cost, Family Dynamics, Preoccupation with Food, Negative Aspects, and Planning and Preparation. It was administered five times during a 1‐year weight‐loss trial (n = 186 women) and once as an online survey in a separate sample (n = 510 adults). Confirmatory factor analysis was used to assess and refine the DSat‐45 structure, and reliability and validity data were examined in both samples for the revised questionnaire, the DSat‐28. Associations were examined between both DSat questionnaires and weight loss in the trial.ResultsInternal consistency (reliability) was moderate for the DSat‐45. Confirmatory factor analysis showed improved fit for a five‐factor structure, resulting in the DSat‐28 that retained four of the original scales and a shortened fifth scale. This revised questionnaire was reliable in both samples. Weight loss across the year‐long trial was positively related to satisfaction with Healthy Lifestyle, Preoccupation with Food, and Planning and Preparation in both versions of the questionnaire.ConclusionsMeasures of reliability and validity were improved in the more concise DSat‐28 compared to the DSat‐45. This shorter measure should be used in future work to evaluate satisfaction with weight‐management diets.

SummaryObjectiveIdentifying early predictors of weight loss is key for developing personalized treatment. However, few individual factors have been identified that predict weight loss during intervention, other than early weight loss itself.MethodsWomen with overweight or obesity (n = 186, mean ± SD age 50.0 ± 10.6 years, body mass index 34.0 ± 4.2 kg m−2) participated in the Portion‐Control Strategies Trial, a 1‐year randomized controlled weight‐loss trial with three intervention groups. Early changes in eating behaviours and psychological factors were evaluated by questionnaires at baseline and Month 1. The influence of these early changes on the trajectory of weight loss from baseline to Months 3 and 12 was assessed by random coefficients models.ResultsAlthough there were no differences in weight loss between intervention groups at the end of the trial, certain individual factors were shown to predict both early weight loss at Month 3 and longer‐term weight loss at Month 12. Across all participants, increases in dietary restraint and healthy lifestyle ratings in the first month predicted more rapid weight loss from baseline to Month 3 (P < 0.05) and also predicted more rapid weight loss and slower regain from baseline to Month 12 (both P < 0.01). Early attendance and changes in disinhibition were not associated with subsequent weight loss.ConclusionsChanges in psychological and behavioural measures, such as restraint, in the first month of weight loss intervention predicted longer‐term weight loss in women. Early additional support or tailored treatment could promote long‐term success by reinforcing these behaviours.