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Dissertation Defense: Processing Matters: Neural and Metabolic Responses to Ultraprocessed Foods

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Zach Hutelin

Dissertation Defense: Processing Matters: Neural and Metabolic Responses to Ultraprocessed Foods

Zach Hutelin

Graduate Student, Translational Biology, Medicine, and Health
Graduate Research Assistant, Donnut Lab, Fralin Biomedical Research Institute at VTC
May 1, 2026, at 1 p.m.
Room G101 A/B, 4 Riverside Circle
Visit the Donnut Lab

About this Dissertation

The modern food environment has undergone a rapid shift toward greater degrees of food processing. Under the Nova classification system, ultraprocessed foods (UPFs) are defined as industrially formulated products that undergo multiple physical and chemical transformations and typically contain additives and ingredients not commonly used in household cooking. UPF consumption has been linked to a range of adverse health outcomes, yet UPFs account for the majority of calories consumed in the United States. Although common attributes of UPFs that promote consumption, such as high energy density and macronutrient composition, have been extensively studied, the direct effects of ultraprocessing itself remain comparatively underexamined. To address this gap in knowledge in Chapter 1 we introduce a novel food picture set comprising 28 commonly consumed foods in the United States that differ on degree of processing while still being carefully matched across 26 visual, nutritional, and perceptual properties to enable the controlled investigation of UPF. Additionally, we derived the Nova classifications for these foods with a strong inter-rater reliability from both non-nutrition-credentialed individuals and credentialed nutrition professionals, directly addressing a noted critique of the Nova system. Next, in Chapter 2, we demonstrated that UPF and non-UPF meals matched across multiple nutritional factors elicit distinct post-ingestive metabolic profiles, characterized by amplified insulinemic and energetic responses and attenuated carbohydrate oxidation following UPF consumption. These processing-related metabolic differences were associated with differential neural responses within reward circuitry to food cues varying in degree of processing, as assessed using the picture set developed in Chapter 1. Finally, we showed that degree of processing does not alter behavioral indices of value but does alter neural representation, specifically throughout the striatum and occipitotemporal gyrus. Collectively, this work provides support for the concept that food processing influences physiology and brain function through mechanisms extending beyond calories and macronutrient composition alone, while identifying altered nutritional availability from altered physical structure as a plausible contributor to both their consumption and effects on metabolic health.

More About the Candidate and Project

Education

Virginia Tech, Translational Biology, Medicine, and Health, Ph.D. Candidate

Brevard College, B.S., Exercise Science

Training

Graduate Research Assistant, Donnut Lab, Fralin Biomedical Research Institute at VTC

Mentor

Alex DiFeliceantonio, Ph.D.,  Assistant Professor, Fralin Biomedical Research Institute at VTC

Committee Members

  • Brenda M. Davy, Ph.D., RDN, Professor, Department of Human Nutrition, Foods, and Exercise at Virginia Tech
  • Alexandra Hanlon, Ph.D., Associate Professor, Department of Statistics at Virginia Tech, Director of the Center for Biostatistics and Health Data Science
  • Jeff Stein, Ph.D., Assistant Professor, Fralin Biomedical Research Institute at VTC

Publications

  • Hutelin, Z., Ahrens, M., Baugh, M. E., Nartey, N., Herald III, D.L., Hanlon, A. L., & DiFeliceantonio, A. G. (2026). Ultraprocessed foods elicit distinct metabolic and neural responses when compared to non-ultraprocessed foods. medRxiv, 2026.04.10.26350599. DOI: https://doi.org/10.64898/2026.04.10.26350599
  • Hutelin, Z., Ahrens, M., Baugh, M. E., Oster, M. E., Hanlon, A. L., & DiFeliceantonio, A. G. (2024). Creation and validation of a NOVA scored picture set to evaluate ultra-processed foods. Appetite, 107358. DOI: 10.1016/j.appet.2024.107358
  • Baugh, M. E., Ahrens, M. L., Hutelin, Z., Stylianos, C., Wohlers-Kariesch, E., Oster, M. E., Dotson, J., Moon, J., Hanlon, A.L., DiFeliceantonio, A.G. (2023). Validity and reliability of a new whole room indirect calorimeter to assess metabolic response to small-calorie loads. PLOS ONE. DOI: 10.1371/journal.pone.0304030
  • Montalban, E., Walle, R., Castel, J., Ansoult, A., Hassouna, R., Foppen, E., Fang, X., Hutelin, Z., Mickus, S., Perszyk, E.E., Petitbon, A., Berthelet, J., Rodrigues-Lima, F., Cebrian-Serrano, A., Gangarossa, G., Martin, C., Trifilieff, P., Bosch-Bouju C., Small D.M., & Luquet, S.H. (2023). The addiction susceptibility TaqIA/Ankyrin repeat and kinase domain containing 1 kinase (ANKK1) controls reward and metabolism through dopamine receptor type 2 (DR2)-expressing neurons. Biological Psychiatry, 94(5), 424-436. DOI: 10.1016/j.biopsych.2023.02.010
  • Perszyk, E.E., Davis, X.S., Djordjevic, J., Jones-Gotman, M., Trinh, J., Hutelin, Z., Veldhuizen, M.G., Koban, L., Wager, T.D., Kober, H., Small, D.M. (2023). Decoding of imagined, but not real, odors determines food cue reactivity. Nature Metabolism, 5(9), 1483-1493. DOI: 10.1038/s42255-023-00874-z
  • Chen, H. A., Hovens, I., Davis, X.S., Hutelin, Z., Wall, K.M., Small, D.M. (2023) Identification of a novel link between adiposity and visuospatial perception. Obesity, 31(2), 423-433. DOI: 10.1002/oby.23603
  • Baugh M.E., Hutelin, Z., DiFeliceantonio A. (2023). Neural correlates of ‘Liking’ and ‘Wanting’ in short-term eating behaviours and long-term energy balance. Current Opinion in Behavioral Sciences, 48, 101227. DOI: 10.1016/j.cobeha.2022.101227
  • Chen, H. A., Hutelin, Z., Moushey, A. M., Diab, N. S., Mehta, S. K., & Corey, B. (2022). Robotic Cholecystectomies: What are They Good for? –A Retrospective Study-Robotic versus Conventional Cases. Journal of Surgical Research, 278, 350-355. DOI: 10.1016/j.jss.2022.04.074
  • Perszyk, E.E., Hutelin, Z., Trinh, J., Kanyamibwa, A., Fromm, S., Davis, X.S., ... & Small, D.M. (2021). Fat and carbohydrate interact to potentiate food reward in healthy weight but not in overweight or obesity. Nutrients, 13(4), 1203. DOI: 10.3390/nu13041203
  • Cobb, K.M., Chavez, D. A., Kenyon, J.D., Hutelin, Z., & Webster, M.J. (2021). Acetic Acid
    Supplementation: Effect on Resting and Exercise Energy Expenditure and Substrate Utilization. International Journal of Exercise Science, 14(2), 222. DOI: 10.70252/GUNG6262
  • Fromm, S., Perszyk, E.E., Kanyamibwa, A., Wall, K.M., Hutelin, Z., Trinh, J., Davis, X.S., Green, B., Flack, K.D., DiFeliceantonio, A.G., Small, D.M. (2021). Development of MacroPics: A novel food picture set to dissociate the effects of carbohydrate and fat on eating behaviors. Appetite, 159, 105051. DOI: 10.1016/j.appet.2020.105051
Posters
  • Hutelin, Z., Baugh, M.E., Ahrens, M.L., Oster, M.E., Hanlon, A.L., DiFeliceantonio, A.G. Effects of Food Processing on Physiology, Brain, and Behavior. Poster presented at: Society for the Study of Ingestive Behavior 30th Annual Meeting; 2023 July 11 - 15; Portland, Oregon.
  • Hutelin, Z., Baugh, M.E., Ahrens, M.L., Hanlon, A.L., DiFeliceantonio. A.G. Web-based Creation and Validation of a Novel Picture Set Designed to Evaluate Processed Foods. Poster presented at: Translational Biology Medicine and Health Research Symposium, January 18, 2023.
  • Hutelin, Z., Oster, M., Dhami, H., Baugh, M.E., West, J.L., Hanlon, A.L., DiFeliceantonio. A.G. Web- based Creation and Validation of a Novel Picture Set Designed to Evaluate Processed Foods. Poster presented at: Society for the Study of Ingestive Behavior 29th Annual Meeting; 2022 July 12 - 16; Porto, Portugal.
  • Hutelin, Z., Perszyk, E.E., Davis, X.S., Graaf, K., Camps, G., Smeets, P., Veldhuizen, M.G., Small. D.M. The Influence of Sweetness on Carbohydrate Metabolism. Poster presented at: Society for the Study of Ingestive Behavior 28th Annual Meeting; 2021 July 12 - 15; Virtual Meeting.
Oral Presentations
  • Hutelin, Z., Baugh, M.E., Ahrens, M.L., Herald III, D.L., Hanlon, A.L., DiFeliceantonio, A.G. Processing Matters: Neural and Metabolic Responses to Ultra- vs Minimally Processed Foods. Talk accepted to be given at: The Obesity Society Annual Meeting; 2025 Nov. 4 – 7; Atlanta, Georgia.
  • Hutelin, Z., Baugh, M.E., Ahrens, M.L., Herald III, D.L., Hanlon, A.L., DiFeliceantonio, A.G. Contrasting metabolic and neural responses to ultra- and minimally processed foods. Talk given at: Society for the Study of Ingestive Behavior 32nd Annual Meeting; 2025 July 28 – Aug 2; Oxford, United Kingdom.
  • Hutelin, Z., Baugh, M.E., Ahrens, M.L., Hanlon, A.L., DiFeliceantonio. A.G. Contrasting Metabolic and Neural Responses to Ultra- and Minimally Processed Foods. Talk given at: Fralin Biomedical Research Institute: Research in Progress Seminar, April 1, 2025.
  • Hutelin, Z., Baugh, M.E., Ahrens, M.L., Herald III, D.L., Hanlon, A.L., DiFeliceantonio. A.G. Differential Metabolic and Brain Responses to Ultra-processed and Minimally Processed Foods. Talk given at: Annual Mid-Atlantic Diabetes and Obesity Research Symposium; Sep. 27, 2024; National Institutes of Health.
  • Hutelin, Z., Baugh, M.E., Ahrens, M.L., Hanlon, A.L., DiFeliceantonio, A.G. Differential Metabolic and Brain Responses to Ultra-processed and Minimally Processed Foods. Talk given at: Society for the Study of Ingestive Behavior 31st Annual Meeting; 2024 July 9 – 14; Chicago, Illinois.
  • Hutelin, Z. Why do We Eat What We Eat? Specific Effects of Ultra-processed Food. Talk given at: Fralin Biomedical Research Institute: Annual Retreat, June 13, 2024.
  • Hutelin, Z., Baugh, M.E., Ahrens, M.L., Hanlon, A.L., DiFeliceantonio. A.G. Differential Metabolic and Brain Responses to Ultra-processed and Minimally Processed Foods. Talk given at: Fralin Biomedical Research Institute: Research in Progress Seminar, March 19, 2024.
  • Hutelin, Z., Baugh, M.E., Ahrens, M.L., Hanlon, A.L., DiFeliceantonio. A.G. The Impact of Ultra-processed Foods on Brain, Metabolism, and Behavior. Talk given at: Fralin Biomedical Research Institute: Research in Progress Seminar, January 31, 2023.
  • Graduate Research Fellowship Program (GRFP), National Science Foundation 2023 - 2026


  • Best Graduate Student Oral Presentation at Society for the Study of Ingestive Behavior (SSIB) 2025


  • Rolls-Simons Travel Award, The Obesity Society 2025


  • Speaker at Virginia Tech Ut Prosim Society (Interviewed by University President) 2025


  • New Investigator Travel Award (NITA), Society for the Study of Ingestive Behavior 2024


  • Best Graduate Student Poster Presentation at Society for the Study of Ingestive Behavior (SSIB) 2023