School of Psychology
Non Technical Summary
The first year of college is a time of transition when adolescents are first learning to manage their own energy intake and expenditure without parental supervision. Many students obtain their meals on campus and are confronted with a wide array of food choices without any limitation on options or portion sizes. Not surprisingly, researchers have documented a consistent weight gain in first-year undergraduates averaging 1-4 kg, resulting in a substantially greater proportion of freshman classified as overweight at the end of the first semester (25.2%) than the beginning (15.6%).Thus, the first year of college is considered a critical period for weight gain for adolescents and consequently a target for prevention. Systemic changes in the food delivery systems on college campuses have the potential to reach a large number of students with an overall low cost, if they can be shown to be effective in preventing obesity. Obesity prevention symbolizes a core philosophical tension between individual freedom and government/institutional actions designed to promote public welfare. Manipulations of available options, such as default choices in decision contexts, represent a compromise between the two; public policies can determine the optimal default positions, yet the choice remains with the individual to opt out. The proposed study will be the first to test the concept of optimal defaults around obesogenic behaviors in college students. By systematically manipulating the health value of the default mode, the experiment in this study examines how hard individuals will work to remain in or obtain healthy choices in the context of the college dining system. Specifically, we will randomize participants to one of three conditions in an experimental meal paradigm: (a) an optimal default lunch, (b) a sub-optimal default lunch, or (c) a free-choice array lunch. We hypothesize that making the default options more optimal (less obesogenic) will lead to more frequent choice of healthier foods (yielding less caloric intake, and more fruit and vegetable consumption) than either the suboptimal default or free array lunches. A major long-term goal of the body of proposed current and future work is sustainable institution-based policy implementation regarding food that will extend beyond the duration of the project. Specifically, results of these experiments will inform policies regarding default selection procedures in college and university dining programs.
Animal Health Component
Research Effort Categories
Goals / Objectives
This project examines how the manipulation of the default mode (i.e., the usual and customary decisions that are made preemptively for the public unless they opt out) may serve as a critical strategy in the prevention of adolescent obesity. By systematically manipulating the health value of the default mode, the experiment outlined in this proposal examines how hard individuals will work to remain in or obtain healthy choices in the context of the college dining system. Specifically, this study aims to generate new knowledge about the behavioral and environmental factors that influence excessive weight gain among youth by studying the effects of optimal (healthy) defaults in the dining experience of first year college students, a group at high risk for weight gain. We will randomize participants to one of three conditions in an experimental meal paradigm: (a) an optimal default lunch, (b) a sub-optimal default lunch, or (c) a free-choice array lunch. Age- and gender- adjusted calories consumed will be the primary outcome variable. The secondary outcome variable will be quantity of fruit and vegetable consumption (servings). We hypothesize that making the default options more optimal (less obesogenic) will lead to more frequent choice of healthier foods (yielding less caloric intake, and more fruit and vegetable consumption) than either the suboptimal default or free array lunches. The first 6 months of the grant will be spent (a) designing the specific menus for the experiments and calculating their precise caloric contents; (b) conducting palatability checks of the menu items with first year college students; (c) developing the demographic questionnaire and food preference inventory specific to this study; (d) procuring and designing materials for the experiment; (e) interviewing and hiring graduate student research assistants; (f) training research assistants and establishing inter-rater reliability in food measurement methods; and (g) developing recruitment materials and actively recruiting for the study. The following 12 months will be spent running the weekly experiments and entering data. The final 6 months of the study will be spent completing data entry, conducting data analysis, writing up the experiments for publication, and disseminating the findings via conference presentations and to college administrators and communities. The fundamental research from this pilot study will inform several aspects of a future Integrated Research, Education, and Extension to Prevent Childhood Obesity proposal, including: (a) expansion of college-based optimal default experiments to include energy expenditure (exercise) in addition to energy intake paradigms, (b) applied research in the form of a college-wide preventive intervention for late adolescent obesity that incorporates optimal defaults in the dining environment, and uses a longitudinal design, (c) teaching and training for doctoral-level graduate students in obesity prevention research and strategies, and (d) targeted outreach efforts to other colleges to shift default health-related environmental conditions to be more optimal.
We will conduct a randomized, between-subjects, 3-condition experiment to test the dietary effects of optimal vs. suboptimal vs. free choice array food presentations in first year college students' dining experience. The sample will consist of 135 first year college students. Data will be analyzed with a one-way ANCOVA to test for a main effect of condition on calories consumed, with participant gender and BMI entered as covariates. In addition, we will use the Tukey Post-Hoc test to examine pair-wise comparisons between any two of the three conditions if the overall model is significant. This same approach will be used to test our secondary outcome variable, servings of fruits/vegetables consumed. Participants will receive a standardized pre-packaged pre-load breakfast (to minimize variability in hunger/satiety across participants) following the informed consent process, measurement of BMI on a physician's balance scale with stadiometer, and completion of a demographic questionnaire and measures to assess predictor variables. They will return at lunchtime for the experimental meal in a private dining room. In the optimal default condition, the foods readily available will be healthy, displayed in pre-packaged individual servings. Healthy will be defined as high nutrient, low energy-dense items. There will also be a menu in a stand on the table that lists the foods available in large print; at the bottom of the menu, in smaller print, a list of alternate, unhealthy (lower nutrient, high energy-dense) items will be noted to be available, but requiring a 15 minute wait to obtain. Participants may choose any combination of items from the default display or the alternate menu, to mimic the allowance of choice typical in a college dining hall. All food items will be pre-measured and calculated for macronutrient analysis. Selected foods will be noted in a check-out station. Participants will be instructed to leave their trays at the conclusion of their meal, and the researchers will calculate percent of food left on the plate, and calories and fruits and vegetables consumed by subtracting leftovers from the checked-out items. We will train research assistants in evidence-based methods to rate percent of food leftover and establish good inter-rater reliability prior to the study. We will use an energy density cut-off of 1 kcal/gram for fruits and vegetables as our secondary dependent variable. In the sub-optimal default condition, the conditions will be reversed in that the default lunch will consist of the less healthy items, and participants will have to actively opt out of such items and wait for the healthier options if desired. In the free array condition, both healthy and unhealthy items will be displayed simultaneously, with no wait for any item. This represents the control condition, most similar to the standard college dining environment and mechanisms of choice within. Final steps of the project include disseminating the findings via conference presentations and to college administrators and communities to inform shifts in default health-related environmental conditions to be more optimal.