People make food choices based upon the motivation to consume foods that are reinforcing compared to alternatives that may be available.1 Delay discounting (DD) is a measure used to assess impulsivity, quantifying how people make decisions based on time to receive and amount of the choice presented. The food purchase task (FPT) assesses the demand for a food and how reinforcing this item is at various prices. Using a controlled feeding study design, 10 males (n=7 sedentary, n=10 endurance trained) consumed an iso-caloric, standard diet (55% carbohydrate, 30% fat, and 15% protein) for 10 days, followed by a high-fat diet (55% fat, 30% carbohydrate, 15% protein) for 5 days. DD, FPT, and Three Factor Eating Questionnaire (TFEQ) were assessed at three time points: baseline, after the standard diet/before high-fat diet, and after the high-fat diet. Discounting rates were significantly different at baseline between sedentary and endurance trained males, with the sedentary males having higher discounting rates (mean difference 1.43, p=.037). Discounting rates for the whole sample significantly decreased between baseline (time 1) and post-STD diet/before HFD (time 2), between time 2 and after the HFD (time 3), and between time 1 and time 3 (all indicated by p<0.05). No group differences were noted over time for demand elasticity, intensity, or TFEQ measures (all indicated by p<0.05). Results could be used to advance the understanding of factors that influence impulsive and unhealthy eating behaviors and inform the development of interventions that use reinforcers to positively influence eating behaviors. / MS / Choice is a fundamental part of life, and people make decisions based on a variety of different factors, such as the amount of effort required, perceived benefits and risks of the choice, what other options are available, and what resources the person has available to them (e.g., time, money). Many dietary and lifestyle choices are unhealthy, such as choosing to consume fast food in excess or to not engage in exercise. About 2/3 of Americans are overweight, and 1/3 are obese, and about 1 in 5 of American adults meet the guidelines recommended by the Centers for Disease Control of engaging in at least 150 minutes of moderate physical activity or 75 minutes of vigorous physical activity per week. Understanding the factors that influence unhealthy eating and lack of physical activity is crucial in order to develop effective programs that focus on changing these behaviors, as weight-loss or physical activity programs often require people to delay the immediate gratification of food in order to achieve optimal health outcomes. The present study investigates how a diet high in fat and exercise habits influence how people value rewards and make decisions. Delayed discounting is a tool used to determine much a person is influenced by immediate gratification of a reward versus waiting for a larger reward of greater worth that is available in the future. The food purchase task is used to quantify the reinforcing value of a food item by determining how much of a favorite snack food a person would purchase by depending on the price. Lastly, eating habits such as dietary restraint or loss of control are quantified by a questionnaire. Results could improve the understanding of factors that influence unhealthy decisions and support the creation of programs that aim to improve how people view and value future health outcomes.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/95951 |
| Date | 13 June 2018 |
| Creators | Privitera, Olivia Frances |
| Contributors | Human Nutrition, Foods and Exercise, Davy, Brenda M., Stein, Jeffrey S., Frisard, Madlyn I. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Detected Language | English |
| Type | Thesis |
| Format | ETD, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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