Marc A. Adams, Ph.D. - US grants

? DESCRIPTION (provided by applicant): Exercise is medicine. Known benefits of moderate-to-vigorous physical activity (MVPA) include improvements to cardiorespiratory fitness, obesity, bone health, cardiovascular disease risk factors, some cancers, and depression and anxiety symptoms. Nevertheless, <8% of US adults as measured by accelerometry meet MVPA guidelines. The majority of existing interventions to increase MVPA have been relatively static (with educational materials or components such as goals to engage in MVPA not changing over time) and at the individual level. Technological and theoretical advances make adaptive interventions (AIs) for MVPA feasible for individuals. Unlike static interventions, AIs have time-varying components that respond uniquely to an individual's performance and changing needs. AIs have potential to reduce treatment mismatch, increase adherence, enhance potency, and personalize behavioral medicine. Micro-incentives (MIs) that are smaller, sooner incentives for goal attainment are possible with technology and hypothesized to result in greater MVPA than larger, later incentives. Combined MIs and AIs have the potential to enhance adoption of MVPA. Additionally, multilevel ecological models posit that physical activity is sensitive to the design of built environments. One core hypothesis derived from ecological models is that low walkable neighborhoods constrain physical activity adoption and maintenance, even in the context of individual-level interventions to increase such behavior. High walkable neighborhoods are hypothesized to provide a supportive environment for PA adoption and maintenance, enhancing the effect of individual-level interventions. Few studies have tested a priori the premise that individual-level interventions result in greater adoption and maintenance of MVPA when conducted in neighborhood environments supportive (vs. unsupportive) of physical activity. Based on our pilot work, we will develop novel adaptive (AI) and micro-incentive (MI) interventions and test them against static (SI) and delayed-incentive interventions (DI) in a 4-arm, randomized factorial trial to increase MVPA among 480 inactive men and women (18-60 years). Using GIS-measured neighborhood walkability and socioeconomic status, we will recruit participants from four neighborhood types: high walkable/high SES, high walkable/low SES, low walkable/high SES, and low walkable/low SES. The factorial design and sampling approach will allow us to test, within a multilevel framework, synergistic or antagonistic interaction effects of interventions and neighborhood factors on MVPA adoption and maintenance. Primary aims of this proposal are to (1) test main and interaction effects for AIs and MIs on MVPA minutes/day by 12 months, (2) investigate whether AIs and MIs foster persistence of MVPA at 18 and 24 months, and (3) determine whether AIs and MIs (compared to SIs and DIs) conducted in high walkable (vs. low walkable) neighborhoods result in greater adoption by 12 months and maintenance of MVPA at 18 and 24 months. Results will inform future hypotheses of ecological models and studies for MVPA adoption and maintenance to improve public health.

Abstract. Building healthy fruit and vegetable (FV) consumption habits early in life are critical for primary prevention of diseases such as cancer and cardiovascular disease. However, youth in the US do not come close to meeting the national recommendations for FV intake. Given that youth consume 1/3-1/2 of their dietary intake in schools and the school meals program serves over 30 million children, major efforts have been made to improve access and subsequent consumption of FVs through the passage of the Healthy Hunger Free Kids Act. Salad bars are one of the most heavily promoted ways to meet the FV regulations in the Healthy Hunger Free Kids Act as a means to increase student FV intake. Let's Move Salad Bars to School, an arm of Let's Move!, Michelle Obama's obesity prevention initiative, has already instituted over 4715 salad bars in schools, with the goal of having a salad bar in every single school, an investment of millions of dollars. Contrary to popular belief, to date, just a single quasi-experimental study has evaluated the efficacy of implementing school salad bars for increasing FVs; this study was conducted with only elementary students from one school district. No studies have examined whether implementing salad bars in middle or high schools increase students' FV consumption. Grounded in the conceptual framework of behavioral economics, the purpose of this study is to examine whether introducing salad bars in elementary, middle, and high schools that have never had salad bars affects students' FV consumption and waste during lunch. A cluster randomized controlled trial will test new salad bars against wait-list controls for 6 weeks, with and without an additional 4- week marketing phase (N=36 schools, N=6804: n=12 elementary, n=12 middle and n=12 high schools). Plate waste measurements of students' selection of FVs and waste will be used to objectively estimate consumption. The primary aim of this study is to compare FV consumption in schools without salad bars to those with new salad bars by grade level (i.e., elementary, middle, high). We hypothesize that students' FV consumption will be greater in schools that implement salad bars. We will examine three secondary aims: a) how FV marketing impacts the success of salad bars at changing FV consumption. We hypothesize that marketing will help to increase FV consumption; b) assess whether salad bars differentially result in more FV plate waste compared to traditional serving methods; c) test the cost-benefit of using salad bars for FV consumption over traditional serving methods in order to provide better evidence to over 100,000 schools serving meals to children participating in the National School Lunch program. A tertiary aim is to examine how salad bar location (inside service line before point of purchase vs. outside service line) is related to FV intake. When the aims of this study are complete, this project stands to be one of the most definitive studies to date on the efficacy of salad bars in schools and contextual factors that promote their success. Findings will provide evidence for how to best spend limited federal dollars to improve FV intake in schools.