The Cleveland Clinic

Weight Loss:
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 as is an average-weight person. This is because obesity has been linked to several serious medical conditions, including:

Doctors generally agree that the more obese a person is the more likely he or she is to have health problems. People who are 20% or more overweight can gain significant health benefits from losing weight. Many obesity experts believe that people who are less than 20% above their healthy weight 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.

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.