Description

Evidence-based weight management programs are effective when individuals are able to consistently adhere to recommendations. However, a large proportion of treatment-seeking individuals do not experience clinically significant weight loss. Innovative strategies are needed to optimize behavior change in weight management interventions. The proposed randomized controlled trial tests two self-regulatory approaches to improve intentional weight loss and diet quality in individuals with overweight or obesity: (1) an environmental control strategy (AVOID) and (2) an impulse control training strategy (RESIST). Specifically, 500 women and men (BMI between 25-45 kg/m2) will be recruited from the Cedars-Sinai Medical Center network of hospitals and clinics. All participants will be enrolled in a 12-month weight-management program (WW, formerly Weight Watchers©) focusing on diet, physical activity and mindset skills, and randomized to one of four study arms: (1) WW only, (2) WW + modification of home food environment and online grocery delivery (AVOID), (3) WW + gamified inhibitory control training (RESIST), (4) WW + AVOID + RESIST. Baseline, 6- and 12-month assessments will be completed by experienced, English and Spanish speaking study staff. Aim 1 (Outcomes). (a) Tests how AVOID and RESIST affect weight loss and waist circumference (primary) and diet quality (secondary). H1a: AVOID and/or RESIST (arms 2, 3, 4) will result in greater weight loss at 6-month and 12-month timepoints compared to WW alone. (b) Tests potential ripple effects of AVOID and RESIST on available household members' diet quality (primary) and weight (secondary). H1b: The investigators predict that AVOID (arms 2 and 4) will produce greater dietary changes in household members than WW alone and RESIST (arms 1 and 3). Aim 2 (Mechanisms). Tests the mechanistic pathways of AVOID and RESIST by (a) comparing longitudinal changes in inhibitory control and home food environment across study arms; and (b) whether inhibitory control and the home food environment mediate the relationships between study arms and anthropometric and dietary outcomes. H2: AVOID will produce changes in the home food environment and RESIST will operate on inhibitory control. Aim 3 (Moderators). Examines how (a) individual characteristics (age, sex, ethnicity, socioeconomic status, household composition, physical activity, baseline BMI and executive functioning), and (b) process data (frequency of grocery delivery, dining out and take out, impulse control training and WW app use) moderate the relationship between study arms and anthropometric and dietary outcomes. These considerations are important to help explain heterogeneity in intervention outcomes and to understand who benefits from AVOID and/or RESIST.