Yaguang Zheng

Abstract

Objective The SELF Trial examined the effect of adding individual self-efficacy (SE) enhancement sessions to standard behavioral weight loss treatment (SBT). Methods Participants were randomly assigned to SBT or SBT plus SE sessions (SBT+SE). Outcome measures were weight loss maintenance, quality of life, intervention adherence, and self-efficacy at 12 and 18 months. Results The sample (N = 130) was female (83.08%) with a mean (SD) body mass index of 33.15 (4.11) kg m2. There was a significant time effect for percent weight change (P = 0.002) yet no significant group or group-by-time effects. The weight loss for the SBT+SE group was 8.38% (7.48) at 12 months and 8.00% (7.87) at 18 months, with no significant difference between the two time points (P = 0.06). However, weight loss for the SBT group was 6.95% (6.67) at 12 months and 5.96% (7.35) at 18 months, which was significantly different between the two time points (P = 0.005), indicating that the SBT group had significant weight regain. Conclusions Both groups achieved clinically significant weight loss. The group receiving an intervention targeting enhanced self-efficacy had greater weight loss maintenance whereas the SBT group demonstrated significant weight regain possibly related to the greater attention provided to the SBT+SE group.

Abstract

Objective Regular self-weighing, which in this article is defined as weighing oneself regularly over a period of time (e.g., daily, weekly), is recommended as a weight loss strategy. However, the published literature lacks a review of the recent evidence provided by prospective, longitudinal studies. Moreover, no paper has reviewed the psychological effects of self-weighing. Therefore, the objective is to review the literature related to longitudinal associations between self-weighing and weight change as well as the psychological outcomes. Methods Electronic literature searches in PubMed, Ovid PsycINFO, and Ebscohost CINAHL were conducted. Keywords included overweight, obesity, self-weighing, etc. Inclusion criteria included trials that were published in the past 25 years in English; participants were adults seeking weight loss treatment; results were based on longitudinal data. Results The results (N = 17 studies) revealed that regular self-weighing was associated with more weight loss and not with adverse psychological outcomes (e.g., depression, anxiety). Findings demonstrated that the effect sizes of association between self-weighing and weight change varied across studies and also that the reported frequency of self-weighing varied across studies. Conclusions The findings from prospective, longitudinal studies provide evidence that regular self-weighing has been associated with weight loss and not with negative psychological outcomes.

Abstract

Background: Evidence supports the role of feedback in reinforcing motivation for behavior change. Feedback that provides reinforcement has the potential to increase dietary self-monitoring and enhance attainment of recommended dietary intake.Objective: The aim of this study was to examine the impact of daily feedback (DFB) messages, delivered remotely, on changes in dietary intake.Methods: This was a secondary analysis of the Self- Monitoring And Recording using Technology (SMART) Trial, a single-center, 24-month randomized clinical trial of behavioral treatment for weight loss. Participants included 210 obese adults (mean body mass index, 34.0 kg/m2) who were randomized to either a paper diary (PD), personal digital assistant (PDA), or PDA plus daily tailored feedback messages (PDA + FB). To determine the role of daily tailored feedback in dietary intake, we compared the self-monitoring with DFB group (DFB group; n = 70) with the self-monitoring without DFB group (no-DFB group, n = 140). All participants received a standard behavioral intervention for weight loss. Self-reported changes in dietary intake were compared between the DFB and no-DFB groups and were measured at baseline and at 6, 12, 18, and 24 months. Linear mixed modeling was used to examine percentage changes in dietary intake from baseline.Results: Compared with the no-DFB group, the DFB group achieved a larger reduction in energy (-22.8% vs -14.0%; P = .02) and saturated fat (-11.3% vs -0.5%; P = .03) intake and a trend toward a greater decrease in total fat intake (-10.4% vs -4.7%; P = .09). There were significant improvements over time in carbohydrate intake and total fat intake for both groups (P values < .05).Conclusion: Daily tailored feedback messages designed to target energy and fat intake and delivered remotely in real time using mobile devices may play an important role in the reduction of energy and fat intake.

Abstract

Background: Outcome expectancy may play an important role in behavior change. Previous studies tested the validity and the reliability of the Perceived Therapeutic Efficacy Scale (PTES), a scale that measures outcome expectancy related to adhering to a cholesterol-lowering diet. Further study was needed to examine its psychometric properties in a larger sample. Objective: The aim of this study was to test the psychometric properties of the 10-item PTES in a large sample. Methods: The PTES and the Connor Diet Habit Survey were administered to adults enrolled in a cardiac rehabilitation program. Results: The final sample for the analysis (N = 224) was, on average, 69.35 years old and was predominantly men (66.50%) and white (92.40%); nearly all (96.00%) completed high school. The inter-item correlation matrix revealed that correlation coefficients were greater than 0.80 between 4 pairs of items, suggesting that the 4 items were redundant. After consulting with a content expert and an examination of item content, we removed the 4 redundant items (items 2, 3, 4, and 10) and reduced the scale to 6 items. Principal component analysis revealed a 1-factor scale with high loadings for the 6 items, each greater than 0.70. The reliability of the scale, measured by Cronbach's α, was 0.91. The total PTES score had a moderate correlation with self-reported behaviors of adhering to a cholesterol-lowering diet, as measured by the Connor Diet Habit Survey subscale for cholesterol and fat intake (r = 0.36, P < 0.05). Conclusions: This study demonstrated that the revised and shortened PTES scale is reliable and valid to measure outcome expectancy related to adhering to a cholesterol-lowering diet.