Doctors generally agree that the more obese a person is the more likely he or she is to have health problems.People who are overweight can gain significant health benefits from losing weight. Losing as little as 5-10% bodyweight can result in significant health benefits. Many obesity experts believe that people who are overweight should still try to lose weight if they have any of the following risk factors.

• Family history of certain chronic diseases. People with close relatives who have had heart disease or diabetes are more likely to develop these problems if they are obese.
• Pre-existing medical conditions. High blood pressure, high cholesterol levels, or high blood sugar levels are all warning signs of some obesity-associated diseases.
• "Apple" shape. People whose weight is concentrated around their stomachs may be at greater risk of developing heart disease, diabetes, or cancer than people of the same weight who are "pear-shaped" (they carry their weight in their hips and buttocks).

Fortunately, even a modest weight loss of 10 to 20 pounds can bring significant health improvements, such as lowering one's blood pressure and cholesterol levels.

How Is Obesity Linked to Heart Disease and Stroke?

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.

The good news is that losing a small amount of weight can reduce your chances of developing heart disease or a stroke. Reducing your weight by 10% can decrease your chance of developing heart disease.

How Is Obesity Linked to Diabetes?

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.

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How Is Obesity and Cancer Linked?

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.

How Is Obesity Related to 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 or cause silent gall stones to become symptomatic. Modest, slow weight loss of about 1 to 2 pounds a week is less likely to cause gallstones. 

How Does Obesity Cause Osteoarthritis?

Osteoarthritis is a common joint condition that most often affects the knee, hip, and lower back joints. Carrying extra pounds places extra pressure on these joints and wear 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.

How Is Obesity Linked to 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.

How Is Obesity Linked to 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.

Reviewed by the Department of Nutrition Therapy at The Cleveland Clinic.
Edited by Kathleen Zelman, MPH, RD, July 25, 2007.
Medically updated July 25, 2007.

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