Document Type


Date of Degree

Summer 2018

Degree Name

PhD (Doctor of Philosophy)

Degree In


First Advisor

Treat, Teresa A.

First Committee Member

Nikolas, Molly A.

Second Committee Member

O'Hara, Michael W.

Third Committee Member

Vander Weg, Mark W.

Fourth Committee Member

Windschitl, Paul D.


Many people track the caloric content of food, given its relevance to weight loss, gain, or maintenance. Thus, better understanding the psychological underpinnings of caloric content estimation for unhealthy foods is of significant psychological and public health interest. This study investigated whether college-aged women could be trained to estimate the caloric content of unhealthy foods more accurately via exposure to caloric content education, trial-by-trial feedback, and their combination. Two hundred and thirty-eight college-aged women estimated the caloric content of 84 photographed foods and completed three transfer tasks. Prior to the first task, women were randomly assigned to one of four groups: Education and Feedback; Education only; Feedback only; or Neither Education nor Feedback. Following the first estimation task, participants estimated the caloric content of 24 novel photographed foods without feedback. Second, participants self-served specified caloric amounts of six real foods. Finally, participants were invited to consume as much as they would like of an unhealthy food in a five-minute period. Mixed-effects modeling estimated three aspects of the quadratic function linking true and judged caloric content: threshold (average perceived caloric content), linear sensitivity, and change in sensitivity as caloric content increases. On average, college-aged women underestimated caloric content, demonstrated substantial linear sensitivity to caloric content, and did not show reduced sensitivity as caloric content increased. Trial-by-trial Feedback, but not Caloric Education, reduced bias in caloric estimation and enhanced sensitivity to caloric content on the first two tasks. There were no effects of Feedback, Education, the interaction between Feedback and Education, BMI, or hunger on the distal transfer tasks. Overall, college-aged women showed biased but sensitive judgments of the caloric content of unhealthy food presented in images. Initial evidence suggests trial-by-trial feedback may be an efficacious strategy to enhance the accuracy of caloric content estimation, at least when viewing static images of foods.


vi, 124 pages


Includes bibliographical references (pages 68-72).


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Copyright © 2018 Marian Tewfik Rizk

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Psychology Commons