Grant: CIHR Fellowship

Background: Obesity is a major risk factor for type 2 diabetes, and it is increasing by epidemic proportions. Weight loss through diet is possible, but often occurs at varying rates, even in highly controlled weight loss programs. This may be due to factors in the muscle that change how we use fats and sugars as energy. Objectives: We will investigate if there are differences in the muscle cells of individuals who lose weight quickly compared to those who lose weight slowly. The Harper laboratory proposes that the different rates of weight loss are due to differences in how the mitochondria (powerhouse of the cell) inside muscle cells use fats and sugars to make energy. Based on previous studies, the Harper laboratory believes that these factors cause the cell to produce molecules, called ROS (reactive oxygen species), that can be harmful to the cell, and this contributes to the variability in weight loss. Experiments: Muscle samples will be collected from women who participate in the professionally supervised Ottawa Hospital Weight Loss Program. We will measure if there are differences in the amount and the function of important proteins that breakdown sugars and fats in the mitochondria and in the amount of ROS between patients who lose weight more or less quickly. We will also grow muscle cells from the collected muscle samples to see if the cells from those who lose weight more slowly break down sugar and fat differently. Significance: This research will help us understand why people lose weight differently. Understanding what biological factors contribute to weight loss is important in developing successful treatment strategies for obesity and type 2 diabetes.