Combined associations of diet quality, physical activity, and their changes over time with cardiometabolic risk and mortality
type: CreativeWork
description: Physical activity (PA) and diet quality have each been shown to be inversely associated with cardiometabolic diseases (CMD), their risk factors, and mortality. However, their combined impact on health outcomes has been less explored, particularly when considering their changes over time. To draw public health messages that can be widely applicable, it is essential to capture long-term dynamic patterns of health behaviours, exploring their possible synergistic, cumulative, or compensatory impacts on various outcomes. The overall aim of my PhD is to evaluate the associations of combined trajectories of diet quality and PA with cardiometabolic risk and longevity. In the first project of my PhD, I systematically reviewed the evidence from prospective observational cohorts on the associations of changes over time in diet quality, PA and combined heath behaviours with cardiometabolic risk and mortality of adults. 17,311 titles were screened and 139 were included in the final synthesis. I developed two meta-analytical methods that allowed pooling of findings. In the first method, I used a dose assignment approach to generate a single effect estimate per study. The analysis demonstrated that increases in PA and diet quality over time were associated with significant risk reductions in a composite outcome of any cardiometabolic diseases - including, but not limited to, cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM) - and mortality. Specifically, for PA, the relative risk reduction was 12% (95% CI: 10–14%) and for diet quality was 6% (95% CI: 3–10%). The second method allowed identification of different trajectories of health behaviours over time and for the same composite outcome, revealed the greatest risk reduction for the “high–high” trajectory (39% [95% CI: 44–33%] for PA and 30% [95% CI: 26–35%] for diet quality). In the second project of my PhD, combined associations of diet quality, PA, and their trajectories with all-cause mortality, cause-specific …
abstract: Physical activity (PA) and diet quality have each been shown to be inversely associated with cardiometabolic diseases (CMD), their risk factors, and mortality. However, their combined impact on health outcomes has been less explored, particularly when considering their changes over time. To draw public health messages that can be widely applicable, it is essential to capture long-term dynamic patterns of health behaviours, exploring their possible synergistic, cumulative, or compensatory impacts on various outcomes. The overall aim of my PhD is to evaluate the associations of combined trajectories of diet quality and PA with cardiometabolic risk and longevity. In the first project of my PhD, I systematically reviewed the evidence from prospective observational cohorts on the associations of changes over time in diet quality, PA and combined heath behaviours with cardiometabolic risk and mortality of adults. 17,311 titles were screened and 139 were included in the final synthesis. I developed two meta-analytical methods that allowed pooling of findings. In the first method, I used a dose assignment approach to generate a single effect estimate per study. The analysis demonstrated that increases in PA and diet quality over time were associated with significant risk reductions in a composite outcome of any cardiometabolic diseases - including, but not limited to, cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM) - and mortality. Specifically, for PA, the relative risk reduction was 12% (95% CI: 10–14%) and for diet quality was 6% (95% CI: 3–10%). The second method allowed identification of different trajectories of health behaviours over time and for the same composite outcome, revealed the greatest risk reduction for the “high–high” trajectory (39% [95% CI: 44–33%] for PA and 30% [95% CI: 26–35%] for diet quality). In the second project of my PhD, combined associations of diet quality, PA, and their trajectories with all-cause mortality, cause-specific …
author: Aryannezhad, Shayan
language: eng
keywords: Adiposity, Cardiometabolic Disease, Cardiometabolic Risk, Cardiovascular Disease, Cohort Study, Diabetes Mellitus, Energy Expenditure, Epidemiology, Mediterranean Diet, Mortality, Nutritional Epidemiology, Physical Activity
license: https://www.repository.cam.ac.uk/bitstreams/3f9cee11-a427-4aa0-a1b6-e8b4b8272bed/download
license: https://creativecommons.org/licenses/by/4.0/
date published: 2025-02-05
date modified: 2026-07-22T22:24:07Z
provider: Cambridge University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Cambridge

PropertyValue
property ID: DOI
value: 10.17863/CAM.120929