What're health risks associated with obesity?
Obesity is not just a cosmetic problem. It's a health hazard. Someone who is 40% overweight is twice as likely to die prematurely than an average-weight person. This is because obesity has been linked to several serious medical conditions including: insulin resistance, heart disease and stroke, high blood pressure, type 2 (adult-onset) diabetes, cancer, gallbladder disease and gallstones, osteoarthritis, gout, breathing problems, such as sleep apnea (when a person stops
breathing for a short time during sleep) and asthma.
Insulin resistance: Insulin is necessary for the transport of blood glucose (sugar) into the cells of muscle and fat (which is then used for energy). By transporting glucose into cells, insulin keeps the blood glucose levels in the normal range. Insulin resistance (IR) is the condition whereby the effectiveness of insulin in transporting glucose (sugar) into cells is diminished. Fat cells are more insulin resistant than muscle cells; therefore, one important cause of IR is obesity. The pancreas initially responds to IR by producing more insulin. As long as the pancreas can produce enough insulin to overcome this resistance, blood glucose levels remain normal. This IR state (characterized by normal blood glucose levels and high insulin levels) can last years. Once the pancreas can no longer keep up with producing high levels of insulin, blood glucose levels begin to rise, resulting in type 2 diabetes, thus IR is a pre-diabetes condition. In fact scientists now believe that the atherosclerosis (hardening of the arteries) associated with diabetes likely develops during this IR period.
Type 2 (adult-onset) diabetes: The risk of type 2 diabetes increases with the degree and duration of obesity. Type 2 diabetes is associated with central obesity; a person with central obesity has excess fat around his/her waist, so that the body is shaped like an apple. Type 2 diabetes reduces your body's ability to control blood sugar. It is a major cause of early death, heart disease, stroke, and blindness. Overweight people are twice as likely to develop type 2 diabetes compared to normal weight people. You can reduce your risk of developing type 2 diabetes by losing weight and exercising more. If you have type 2 diabetes, losing weight and becoming more physically active can help control your blood sugar levels. Increasing your physical activity may also allow you to reduce the amount of diabetes medication you need.
Heart disease and stroke: The Nurses Health Study found that the risk of developing coronary artery disease increased 3 to 4 times in women who had a BMI greater than 29. A Finnish study showed that for every one kilogram (2.2 pounds) increase in body weight, the risk of death from coronary artery disease increased by one percent. In patients who have already had a heart attack, obesity is associated with an increased likelihood of a second heart attack. Heart disease and stroke are the leading causes of death and disability for people in the U.S. Overweight people are more likely to have high blood pressure, a major risk factor for heart disease and stroke, than people who are not overweight. Very high blood levels of cholesterol can also lead to heart disease and often are linked to being overweight. Being overweight also contributes to angina (chest pain caused by decreased oxygen to the heart) and sudden death from heart disease or stroke without any signs or symptoms.
Cancer: Several types of cancer are associated with being overweight. In women, these include cancer of the uterus, gallbladder, cervix, ovary, breast, and colon. Overweight men are at higher risk for developing colorectal cancer and prostate cancer. For some types of cancer, such as colon or breast, it is not clear whether the increased risk is due to the extra weight or to a high-fat, high-calorie diet. While not conclusively proven, some observational studies have linked obesity to cancer of the colon in men and women, cancer of the rectum and prostate in men, and cancer of the gallbladder and uterus in women. Obesity may also be associated with breast cancer, particularly in postmenopausal women. Fat tissue is important in the production of estrogen, and prolonged exposure to high levels of estrogen increases the risk of breast cancer.
Gallbladder disease: Gallbladder disease and gallstones are more common if you are overweight. Your risk of disease increases as your weight increases. It is not clear how being overweight may cause gallbladder disease. Ironically, weight loss itself, particularly rapid weight loss or loss of a large amount of weight, can actually increase your chances of developing gallstones. Modest, slow weight loss of about 1 pound a week is less likely to cause gallstones.
Osteoarthritis: Osteoarthritis is a common joint condition that most often affects the joints in your knees, hips, and lower back. Carrying extra pounds increases the risk of osteoarthritis by placing extra pressure on these joints and wearing away the cartilage (tissue that cushions the joints) that normally protects them. Weight loss can decrease stress on the knees, hips, and lower back and may improve the symptoms of osteoarthritis
Gout: Gout is a disease that affects the joints that is caused by high levels of a substance called uric acid in the blood. The large amount of uric acid can form into solid or crystal-like masses that deposit in the joints. Gout is more common in overweight people and the risk of developing the disorder increases with higher body weights. Over the short term, certain dietary changes may lead to an attack of gout in people who have high levels of uric acid or who have had gout before. If you have a history of gout, check with your doctor before trying to lose weight.
Sleep apnea: Sleep apnea is a serious breathing condition that is associated with being overweight. Sleep apnea can cause a person to snore heavily and to stop breathing for short periods during sleep. Sleep apnea may cause daytime sleepiness and even heart failure. The risk for sleep apnea increases as body weight increases. Weight loss usually improves sleep apnea.