NUTR100 Chapter Notes -Mutation, Gastric Bypass Surgery, Osteoarthritis

• School: University of Alberta
• Department: Nutrition
• Course: NUTR100
• Professor: Sabina Valentine

Document Summary

Thermic effect of food (tef: energy expended to process food. Energy expended in physical activity: energy cost of movement above basal, affected by body size, intensity of exercise, and how long activities are performed. Genetic factors account for about 25% of a persons body fat. Different ideas have been suggested to explain the impact of genetics on body fat: thrifty gene theory, set-point theory. Set- point theory: proposes that each person"s weight stays within a small range (set point, the body compensates for changes in energy balance and keeps a person"s weight at their set point, explains why dieting may not work. Leptin is a hormone produced by fat cells that causes reduced food intake, reduced weight, decreases body fat. Leptin is controlled by the ob gene: mutation of the ob gene causes reduced levels of leptin leading to increased food intake and reduced energy output. Childhood overweight increases the risk of heart disease and premature death as an adult.