eprintid: 10197540 rev_number: 13 eprint_status: archive userid: 699 dir: disk0/10/19/75/40 datestamp: 2024-11-07 08:37:30 lastmod: 2024-11-07 08:37:30 status_changed: 2024-11-07 08:37:30 type: thesis metadata_visibility: show sword_depositor: 699 creators_name: Dicken, Samuel James title: The impact of ultra-processed food intake on health, independent of dietary nutrient quality ispublished: unpub divisions: UCL divisions: B02 divisions: C10 divisions: D17 note: Copyright © The Author 2024. Original content in this thesis is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) Licence (https://creativecommons.org/licenses/by-nc/4.0/). Any third-party copyright material present remains the property of its respective owner(s) and is licensed under its existing terms. Access may initially be restricted at the author’s request. abstract: Increasing evidence suggests that higher ultra-processed food (UPF) intake is associated with numerous health outcomes, including obesity, cardiometabolic disease and mortality. However, whether UPF provides novel diet-related health information is unclear. Using multiple data sources and research methods, this PhD examined whether the health impact of UPF (defined by the Nova classification) is independent of dietary nutrient quality. In Chapter 4, nutrient profiling of food and drink in the UK showed that the Nova classification, nutritional characteristics, and front-of-package labels only partially overlap. This indicates that UPF are not necessarily synonymous with nutritionally poor food, providing rationale for other aspects of UPF impacting on health. In Chapter 5, I demonstrated across a large body of cohort studies that diet/nutrient quality did not explain the associations between UPF and adverse health outcomes. In Chapter 6, I conducted a prospective cohort analysis, showing contrasting associations between UPF and other food processing groups with incident T2DM. Causal inference methods including substitution modelling indicated that replacing UPF with other food processing groups was associated with lower incident T2DM, independent of diet/nutrient quality. However, some UPF sub-groups were inversely associated with incident T2DM, and mediation analysis indicated that the association between UPF and incident T2DM was fully explained by artificially- and sugar-sweetened beverage consumption. In Chapters 7-8, I outlined the protocol for, and challenges in designing/conducting, a real-world, randomised controlled trial, investigating the health effects of a UPF vs. minimally processed diet meeting UK dietary guidance. The thesis results generally support the proposed hypothesis of a significant negative association of UPF on health, that is not explained by dietary nutrient quality/guidelines. However, a grading in terms of the potential adverse health outcomes from UPF was evident. The trial will provide clarity on whether policy action should focus on all UPF, or specific UPF. date: 2024-09-28 date_type: published full_text_type: other thesis_class: doctoral_embargoed thesis_award: Ph.D language: eng verified: verified_manual elements_id: 2321487 lyricists_name: Dicken, Samuel lyricists_id: SDICK76 actors_name: Dicken, Samuel actors_id: SDICK76 actors_role: owner full_text_status: restricted pages: 610 institution: UCL (University College London) department: Centre for Obesity Research thesis_type: Doctoral citation: Dicken, Samuel James; (2024) The impact of ultra-processed food intake on health, independent of dietary nutrient quality. Doctoral thesis (Ph.D), UCL (University College London). document_url: https://discovery.ucl.ac.uk/id/eprint/10197540/1/Dicken_10197540_thesis.pdf