Abstract 041: Effect Of Personalized Feedback Messages On Adherence To The Dietary, Physical Activity And Weight Loss Goals- The Smarter RCT

Background: A core component of standard behavior treatment for weight loss is establishing goals for caloric restriction and weekly minutes of physical activity (PA). Adherence to these behavior change goals is essential for successful weight loss outcomes. The aim of this paper is to examine adherence to the behavior change goals in the two treatment conditions: Self-Monitoring plus personalized Feedback (SM+FB) or SM alone. Methods: We conducted a single-site, two-arm randomized controlled trial from August 2018 to March 2021. Adults (N=502) 18 years of age or over with body mass index (BMI) 27-43 kg/m 2 were randomized with equal allocation to SM+FB (n=251) or SM (n=251). Feedback messages were sent daily for diet and every other day for PA. Adherence to the dietary and PA goals were defined as: 1) for diet the number of days one was adherent to the calorie goal (i.e., between 80% and 120% with the wide range due to the lack of precision in self-reported food intake) and 2) for PA the percentage of minutes of fairly and very active minutes per week meeting the PA goal of at least 150 minutes for fairly and very active minutes based on the Fitbit Charge 2™. Associations between treatment assignment and adherence to the dietary and PA goals were examined using linear mixed modeling with intention-to-treat method. Results: The sample (N=502) was mostly white (84%, 423 of 502), female (79%, 399 of 502) and on average 45.0±14.4 years of age and BMI of 33.7±4.0 kg/m 2 . Study retention at 12 months was 79%. The trajectory of change in adherence to the dietary goal was non-linear over 12 months (b=-.18, 95% CI [-.20, -.17]; b 2 =.006, 95% CI [.005, .007]; b 3 =-.0001, 95% CI [-.00007, -.00006], all P<.0001). The rate of decline over time in adherence to the diet goal was nonlinear and different by treatment (b trt*time = .03, 95% CI [.01, .06]; b trt*time*time = -.002, 95% CI [-.003, -.001]; b trt*time*time*time = .00003, 95% CI [.00002, .00004], all P<.05) Notably, the effect of treatment (b= .41, 95% CI [.10, .72], P=.009) on adherence to the dietary goal was significant. Additionally, the effects of time with polynomial contrasts showed declining curvilinear trajectories of change in the PA goal over 12 months (b=-1.75, 95% CI [-2.57, -0.92], b 2 =.08, 95% CI [.04, .11], b 3 =-.001, 95% CI [-.002, -.001], all P<.0001). The rate of decline over time in adherence to the PA goal was non-linear and different by treatment (b trt*time = -.80, 95% CI [-1.40, -.20]; b trt*time*time = .02, 95% CI [.004, -.03], all P<.05); the effect of treatment on adherence to the PA goal was not significant (b= 19.07, 95% CI [-3.86, 42.01], P = .103). Conclusions: In this study, adherence to the dietary and PA goals was associated with daily FB, which may be related to the frequency of the feedback messages. Further studies are needed to determine the best dose of tailored feedback messages to achieve sustained adherence to the prescribed behavior change goals.

背景： 减肥的标准行为治疗的一个核心组成部分是设定热量限制目标以及每周的身体活动（PA）分钟数目标。坚持这些行为改变目标对于成功的减肥结果至关重要。本文的目的是检验在两种治疗条件下对行为改变目标的坚持情况：自我监测加个性化反馈（SM + FB）或仅自我监测（SM）。 方法： 我们于2018年8月至2021年3月进行了一项单中心、双臂随机对照试验。年龄在18岁及以上、体重指数（BMI）为27 - 43 kg/m²的成年人（N = 502）被随机平均分配到SM + FB组（n = 251）或SM组（n = 251）。饮食方面每天发送反馈信息，身体活动方面每隔一天发送反馈信息。对饮食和身体活动目标的坚持定义如下：1）对于饮食，坚持热量目标的天数（即由于自我报告的食物摄入量缺乏精确性，在80% - 120%之间）；2）对于身体活动，根据Fitbit Charge 2™，每周达到至少150分钟中等及高强度活动分钟数目标的中等及高强度活动分钟数的百分比。使用线性混合模型和意向性分析方法检验治疗分配与对饮食和身体活动目标的坚持之间的关联。 结果： 样本（N = 502）主要为白人（84%，502人中有423人），女性（79%，502人中有399人），平均年龄为45.0 ± 14.4岁，BMI为33.7 ± 4.0 kg/m²。12个月时的研究留存率为79%。12个月内对饮食目标的坚持变化轨迹是非线性的（b = -0.18，95%置信区间[ - 0.20， - 0.17]；b² = 0.006，95%置信区间[0.005，0.007]；b³ = - 0.0001，95%置信区间[ - 0.00007， - 0.00006]，所有P < 0.0001）。随着时间推移对饮食目标的坚持率下降是非线性的，且因治疗方式而异（b_trt*time = 0.03，95%置信区间[0.01，0.06]；b_trt*time*time = - 0.002，95%置信区间[ - 0.003， - 0.001]；b_trt*time*time*time = 0.00003，95%置信区间[0.00002，0.00004]，所有P < 0.05）。值得注意的是，治疗对坚持饮食目标的影响是显著的（b = 0.41，95%置信区间[0.10，0.72]，P = 0.009）。此外，多项式对比的时间效应显示，12个月内身体活动目标的变化呈下降的曲线轨迹（b = - 1.75，95%置信区间[ - 2.57， - 0.92]，b² = 0.08，95%置信区间[0.04，0.11]，b³ = - 0.001，95%置信区间[ - 0.002， - 0.001]，所有P < 0.0001）。随着时间推移对身体活动目标的坚持率下降是非线性的，且因治疗方式而异（b_trt*time = - 0.80，95%置信区间[ - 1.40， - 0.20]；b_trt*time*time = 0.02，95%置信区间[0.004， - 0.03]，所有P < 0.05）；治疗对坚持身体活动目标的影响不显著（b = 19.07，95%置信区间[ - 3.86，42.01]，P = 0.103）。 结论： 在这项研究中，对饮食和身体活动目标的坚持与每日反馈相关，这可能与反馈信息的频率有关。需要进一步的研究来确定定制反馈信息的最佳剂量，以实现对规定的行为改变目标的持续坚持。