says who? Obesity A study of nearly 10,000 adults examined the relationship between obesity and lack of sleep. The study concluded that individuals between the ages of 32 and 49 who get less than seven hours of sleep each night were significantly more likely to be obese. A lack of sleep can disrupt the production of hormones ghrelin and leptin, which are responsible for regulating appetite, causing a variety of weight-related problems including obesity. Mood Disorders A loss of sleep may result in irritability, impatience, inability to concentrate and even moodiness and depression. A lack of sleep results in an increase in cortisone levels — the body’s stress hormone, leading to the development of mood disorders including depression and anxiety. Memory High school and college students often pull “all-nighters” during exam time. While they may assume that studying all night will help them be better prepared for the morning’s exam, this couldn’t be further from the truth. During sleep, the brain is actively working to store new information you learned during the day. This process of retaining information is called memory consolidation. Getting fewer than six hours of sleep disrupts this process, making it more difficult to recall information. For best test scores, it’s best to get a full night’s sleep before an exam. Immunity Sleep deprivation alters the body’s immune functions, making you more susceptible to colds and other deadly diseases such as cancer. Getting less than the recommended six hours of sleep reduces the body’s white blood cells — the body’s defense against disease. A lack of sleep may also put the body into a state of high alert, increasing the production of stress hormones and blood pressure putting you at risk for a heart attack or stroke.