Department of Nutrition Sciences, University of Alabama at Birmingham (UAB), Birmingham, AL 35294, USA.
Department of Health Behavior, University of Alabama at Birmingham (UAB), Birmingham, AL 35294, USA.
Nutrients. 2023 Nov 25;15(23):4918. doi: 10.3390/nu15234918.
Mechanisms that explain behavior change within web-based lifestyle interventions are not well-studied. This secondary analysis explores whether the effects of the DUET web-based lifestyle intervention on diet, physical activity, and/or adiposity are mediated through changes in self-efficacy, social support, and perceived barriers (key constructs of social cognitive theory). Data on mediators, diet quality, caloric intake, moderate-to-vigorous physical activity (MVPA), weight, and waist circumference (WC) were analyzed from 112 cancer survivors and their partners enrolled in the DUET intervention. Mediation analyses were performed using Mplus to execute regression analyses and determine associations. Mediation analyses supported an effect of the intervention on caloric intake (-3.52, 95% CI [-8.08 to -0.84]), weight (-1.60, CI [-3.84 to -0.47]), and WC (-0.83, CI [-1.77 to -0.18]), interpreting these negative associations as intervention induced reductions in dietary barriers. Higher social support was significantly and positively associated with, but not a mediator for, improvements in self-reported and accelerometry-measured MVPA (b = 0.69, CI [0.19, 1.24]) and (b = 0.55, CI [0.15, 1.00]), respectively. Self-efficacy did not appear to mediate the intervention's effects. Findings suggest that the effects of the DUET intervention on diet and adiposity stem from reducing perceived barriers to a healthful, low-calorie diet.
机制解释基于网络的生活方式干预行为变化尚未得到很好的研究。这项二次分析探讨了基于网络的生活方式干预 DUET 对饮食、身体活动和/或肥胖的影响是否通过自我效能感、社会支持和感知障碍（社会认知理论的关键构建）的变化来介导。对饮食质量、热量摄入、中等到剧烈体力活动（MVPA）、体重和腰围（WC）的中介物数据进行了分析，共分析了 112 名癌症幸存者及其参与 DUET 干预的伴侣。使用 Mplus 进行中介分析，以执行回归分析并确定关联。中介分析支持干预对热量摄入（-3.52，95%CI [-8.08 至-0.84]）、体重（-1.60，CI [-3.84 至-0.47]）和 WC（-0.83，CI [-1.77 至-0.18]）的影响，将这些负向关联解释为干预引起的饮食障碍减少。较高的社会支持与自我报告和加速度计测量的 MVPA 的改善显著正相关（b = 0.69，CI [0.19，1.24]）和（b = 0.55，CI [0.15，1.00]），但不是中介因素。自我效能感似乎没有介导干预的效果。研究结果表明，DUET 干预对饮食和肥胖的影响源于减少健康、低热量饮食的感知障碍。
