Directly from the Surgeon General
Overweight and Obesity: Health Consequences
The primary concern of overweight and obesity is one of health and not appearance.
An estimated 300,000 deaths per year may be attributable to obesity.
The risk of death rises with increasing weight.
Even moderate weight excess (10 to 20 pounds for a person of average height) increases the risk of death, particularly among adults aged 30 to 64 years.
Individuals who are obese (BMI > 30)* have a 50 to 100% increased risk of premature death from all causes, compared to individuals with a healthy weight.
The incidence of heart disease (heart attack, congestive heart failure, sudden cardiac death, angina or chest pain, and abnormal heart rhythm) is increased in persons who are overweight or obese (BMI > 25).*
High blood pressure is twice as common in adults who are obese than in those who are at a healthy weight.
Obesity is associated with elevated triglycerides (blood fat) and decreased HDL cholesterol ("good cholesterol").
A weight gain of 11 to 18 pounds increases a person's risk of developing type 2 diabetes to twice that of individuals who have not gained weight.
Over 80% of people with diabetes are overweight or obese.
Overweight and obesity are associated with an increased risk for some types of cancer including endometrial (cancer of the lining of the uterus), colon, gall bladder, prostate, kidney, and postmenopausal breast cancer.
Women gaining more than 20 pounds from age 18 to midlife double their risk of postmenopausal breast cancer, compared to women whose weight remains stable.
Sleep apnea (interrupted breathing while sleeping) is more common in obese persons.
Obesity is associated with a higher prevalence of asthma.
For every 2-pound increase in weight, the risk of developing arthritis is increased by 9 to 13%.
Symptoms of arthritis can improve with weight loss.
Complications of pregnancy
Obesity during pregnancy is associated with increased risk of death in both the baby and the mother and increases the risk of maternal high blood pressure by 10 times.
In addition to many other complications, women who are obese during pregnancy are more likely to have gestational diabetes and problems with labor and delivery.
Infants born to women who are obese during pregnancy are more likely to be high birthweight and, therefore, may face a higher rate of Cesarean section delivery and low blood sugar (which can be associated with brain damage and seizures).
Obesity during pregnancy is associated with an increased risk of birth defects, particularly neural tube defects, such as spina bifida.
Obesity in premenopausal women is associated with irregular menstrual cycles and infertility.
ADDITIONAL HEALTH CONSEQUENCES
Overweight and obesity are associated with increased risks of gall bladder disease, incontinence, increased surgical risk, and depression.
Obesity can affect the quality of life through limited mobility and decreased physical endurance as well as through social, academic, and job discrimination.
CHILDREN AND ADOLESCENTS
Risk factors for heart disease, such as high cholesterol and high blood pressure, occur with increased frequency in overweight children and adolescents compared to those with a healthy weight.
Type 2 diabetes, previously considered an adult disease, has increased dramatically in children and adolescents. Overweight and obesity are closely linked to type 2 diabetes.
Overweight adolescents have a 70% chance of becoming overweight or obese adults. This increases to 80% if one or more parent is overweight or obese.
The most immediate consequence of overweight, as perceived by children themselves, is social discrimination.
BENEFITS OF WEIGHT LOSS
Weight loss, as modest as 5 to 15% of total body weight in a person who is overweight or obese, reduces the risk factors for some diseases, particularly heart disease.
Weight loss can result in lower blood pressure, lower blood sugar, and improved cholesterol levels.
A person with a Body Mass Index (BMI) above the healthy weight range* may benefit from weight loss, especially if he or she has other health risk factors, such as high blood pressure, high cholesterol, smoking, diabetes, a sedentary lifestyle, and a personal and/or family history of heart disease.
*Please see fact sheet "Measuring Overweight and Obesity" for a definition of BMI.