UPDATED: Is obesity a disease? – The United States is the second most obese industrialized nation in the world with 31.8% of Americans classified as obese in 2013. Proponents contend that obesity is a disease because it meets the definition of disease; it decreases life expectancy and impairs the normal functioning of the body; and it can be caused by genetic factors. Opponents contend that obesity is not a disease because it is a preventable risk factor for other diseases; is the result of eating too much; and is caused by exercising too little. Visit our site to learn more and decide for yourself.