METABOLISM Definition: Meta means changing or transforming Metabolism refers to the entire network of chemical processes in maintaining life 2 separate pathways o Catabolism – breaking down complex molecules into simpler ones o Anabolism -building complex molecules (living tissue) from simple ones Main function of metabolism is to maintain homeostasis (maintaining balance in the body’s internal environment e.g. blood glucose) (see Ch. 14 in Food Science). Metabolic Rate: refers to the rate at which the body’s chemical processes occur Variations in Metabolic Rate do occur due to variations in Body temperature Body size (determined by genetic, behavioural, environmental factors) Physical development and age Body composition and sex Supply of energy available to the body (conservation/survival) Metabolism and Weight Management: metabolic rate influences weight maintenance Basal metabolism – energy used by body at rest to maintain automatic lifesupporting processes such as breathing, maintaining body temperature, regulating heartbeat, as well as cellular processes. o BMR consumes about 2/3 of your body’s energy Voluntary Activities – consumes the remaining 1/3 of body’s energy o Includes all physical activity – sedentary, light, moderate, vigorous Weight-loss Diets – body switches to ‘survival mode’ (SET POINT) Physical exercise – increases metabolic rate