Factors influencing heterogeneity in anthropometric and metabolic responses to structured lifestyle interventions
Date
2024-04-16Embargo Date
2025-04-03
Author
Finucane, Francis Martin
Metadata
Show full item recordUsage
This item's downloads: 0 (view details)
Abstract
The rising prevalence of obesity is a significant burden on affected individuals, on healthcare systems
and on society. Diet and physical activity are critical determinants of body weight and obesity risk,
and lifestyle modification is the cornerstone of the therapeutic approach to obesity. However, there
is substantial inter-individual variation in responses to lifestyle modification. In this work, I examine
some of the factors associated with variations in anthropometric and metabolic responses to
structured lifestyle modification programmes.
Firstly, I conducted a prospective cohort study of patients with severe obesity completing a
structured diet and exercise programme, noting that older patients, males and those with lower
levels of depression were more likely to complete the programme, and were more likely to achieve
≥5% weight loss. I found strong and consistent associations between the amount of weight lost and
the magnitude of improvements in markers of mental, metabolic and cardiovascular health.
Secondly, I completed a post hoc analysis of the Hertfordshire Physical Activity Trial, describing the
effect of a supervised, structured 12-week aerobic exercise intervention on objectively measured
physical activity energy expenditure in healthy older adults. There was no significant effect of the
exercise intervention on overall average physical activity, but there was an effect on the three days
of the week that the exercise sessions took place, suggesting that the frequency of exercise bouts,
rather than their intensity or duration, may not have been adequate to exact an overall effect of the
intervention.
Thirdly, I conducted a cohort analysis from the same trial, describing a strong and consistent
association between physical activity energy expenditure and body fat, cardiovascular risk and
various measures of insulin resistance, in healthy older adults. However, changes in physical activity
were only associated with improvements in some of those outcomes, suggesting that the metabolic
benefits of physical activity take longer than 12 weeks to become apparent.
Fourthly, in a retrospective cohort study of adults with severe obesity completing a milk-based meal
replacement programme, I found that a genetic risk score derived from common polymorphisms
associated with central fat distribution was inversely associated with the magnitude of weight loss,
the first Irish study to confirm a genetic influence on the response to a dietary intervention.
Finally, in a prospective cohort study in patients undergoing the milk diet, I described associations
between changes in fasting plasma ketone concentrations and weight loss. This has led to securing
research funding from Science Foundation Ireland to explore the relevance of physiological ketosis in
predicting and mediating responses to clinical interventions for patients with obesity, at CÚRAM.