Exploring the effects of exercise and dietary protein on mechanisms of muscle mass preservation in obese older adults during weight loss

Changing population demographics have increased the global number of older adults. Alongside this, obesity rates are soaring, which presents a considerable burden to health and social care expenditure. Reducing energy intake in the diet is an effective to reduce obesity and fat mass. However, weight loss through dieting typically causes some degree of muscle mass loss as well, which could accelerate the risk of disability and disease in older adults. The current project aims to explore the effect of exercise training and protein nutrition to spare muscle mass loss in older adults with obesity during a short-term period of dietary energy restriction. Initially, we will use sophisticated microscope techniques to explore the effect of obesity on the factors that regulate muscle cell size and metabolism by using skeletal muscle biopsies obtained from healthy young and older adults and older adults with obesity. We will then conduct a randomised controlled trial in older adults to understand the extent to which increasing dietary protein nutrition with or without exercise training, influences changes in body tissue composition during a short-term period of weight loss. To achieve this, we will use detailed and precise methods to measure body tissue compartments and the rate at which muscle mass is built. This project will help characterise the mechanisms through which obesity speeds up muscle deterioration in older age. In addition, this project with help us understand how lifestyle interventions of exercise and nutrition can promote high quality weight loss that has important implications for long term health and quality of life in our increasingly obese and ageing societies.