About one-third of the U.S. population is overweight. Excess body weight--and, in particular, male pattern obesity characterized by excess abdominal fat as opposed to fat accumulation in the thighs and buttocks-- is implicated as a risk factor for many different diseases. Therefore, maintaining a healthy body weight is prudent. Unfortunately, keeping lost weight off is very difficult for most people.
Health Problems Associated with Obesity
(The following list is comprehensive, although not necessarily exhaustive. Contact your health care professional for more information.)
Benign Prostatic Hyperplasia (BPH)The prostate is a small gland that surrounds the neck of the bladder and urethra in men. Its major function is to contribute to seminal fluid. If the prostate enlarges, pressure can be put on the urethra, acting like a partial clamp and causing related symptoms. This condition is known as benign prostatic hyperplasia (BPH). Obesity has been linked to an increased risk of developing BPH.1
CancerCancer is a general term for more than 100 diseases that are characterized by uncontrolled, abnormal growth of cells. Cancer is the second leading cause of death in Americans. Obesity has been linked to cancers of the endometrium, colon, kidney, and breast (in postmenopausal women only) and possibly to cancers of the ovary and prostate.2
Cardiovascular DiseaseCardiovascular disease is the number one cause of death in the United States. Obesity increases the risk of cardiovascular disease.3 Obesity is associated with increased risk for heart attack, particularly among younger people.4 One study found this relationship increased in women who also had a history of diabetes or high cholesterol.5 Nutritionally oriented doctors encourage people who are at risk for heart attack and are overweight to lose the extra weight and keep it off.
Cholesterol (High)Although it is by no means the only major risk factor, elevated serum cholesterol is clearly associated with a high risk of heart disease. Obesity increases the risk of heart disease,6 in part because weight gain lowers HDL cholesterol (the "good" cholesterol).7 Weight loss increases HDL,8 thereby reducing (improving) the ratio between total cholesterol and HDL, a change linked to lowered risk of heart disease.
DiabetesPeople with diabetes cannot properly process glucose, a sugar the body uses for energy. As a result, glucose stays in the blood, causing blood glucose to rise. At the same time, however, the cells of the body can be starved for glucose. Diabetes can lead to poor wound healing, higher risk of infections, and many other problems involving the eyes, kidneys, nerves, and heart. Most people with type 2, or non-insulin dependent diabetes mellitus, are obese.9 Excess abdominal weight does not stop insulin formation,10 but it does make the body insensitive to insulin.11 Excess weight even makes healthy people pre-diabetic.12 Weight loss reverses this problem.13 Type 2 improves with weight loss in most studies.14,15,16 Being overweight does not cause type 1, or insulin dependent diabetes mellitus, but it does increase the need for more insulin. Therefore, people with type 1 should achieve and maintain appropriate body weight.
GallstonesGallstones are formed in the gallbladder and primarily consist of cholesterol. They are commonly associated with bile that contains excessive cholesterol, a deficiency of other substances in bile (bile acids and lecithin), or a combination of these factors. Some,17 but not all studies have found apparent links between obesity and increased risk of gallstone formation.18
HypertensionHypertension is the medical term for high blood pressure. The cause of most hypertension remains unknown. Many people with high blood pressure are overweight. Weight loss can lower blood pressure significantly in those who are both overweight and hypertensive.19 People with hypertension who are overweight should talk with a nutritionally oriented doctor about a weight loss program.
Immune FunctionBoth excessive thinness and severe obesity are associated with impaired immune responses,20 and obesity has increased the risk of infection in hospitalized patients according to preliminary research.21 However, these effects may not occur with mild to moderate obesity in otherwise healthy people, and attempts to lose weight through dietary restriction may actually be harmful to the immune system.22 The detrimental effects of both excess weight and weight-loss diets appear to be offset when people regularly perform aerobic exercise.23,24
Infertility (Female)Excessive weight can be a cause of female infertility.25 Infertile women who are overweight should consult a nutritionally oriented physician to develop a weight loss plan.
MortalityA clear association between obesity and increased mortality (higher death rate) has been reported.26
OsteoarthritisOsteoarthritis is a common disease that develops when linings of joints fail to maintain normal structure, leading to pain and decreased mobility. Obesity increases the symptoms suffered by people with osteoarthritis of weight-bearing joints. Weight loss is thought by arthritis experts to be of potential benefit, at least in reducing pain in weight-bearing joints.27
StrokeStrokes are caused either by a lack of blood supply to the brain or by hemorrhage in the brain. Depending on the area of the brain that is damaged, a stroke can cause coma, reversible or irreversible paralysis, speech problems, and dementia. Abdominal obesity has been associated with an increased risk of stroke.28 Smoking (which lower weight but increases the risk of stroke) and other factors sometimes lower the strength of the association between obesity and stroke risk. Nonetheless, scientists believe that being overweight significantly increases the risk of suffering a stroke.29
Triglycerides (High)Most studies indicate that people with elevated triglycerides (a type of fat in the blood) are at higher risk of heart disease. Obesity increases triglyceride levels.30 Maintaining ideal body weight helps protect against elevated triglyceride levels. Many nutritionally oriented doctors encourage overweight people who have elevated triglycerides to lose the extra weight.
Uterine FibroidsObese women are more likely to develop uterine fibroids (benign tumors in the uterus that may cause irregular menses) than non-obese women.31
Work DisabilityObese individuals have a higher risk of having disabilities severe enough to interfere with the ability to work.32
1. Soygur T, Kupeli B, Aydos K, et al. Effect of obesity on prostatic hyperplasia: its relation to sex steroid levels. Int Urol Nephrol 1996;28:55-9.