Weight and health

Excess body weight increases your risk for more than 50 different health problems (see Figure 2). These health conditions include the nation's leading causes of death — heart disease, stroke, and certain cancers — as well as less common ailments such as gout and gallstones.

A Harvard study that combined data from more than 50,000 men (participants in the Health Professionals Follow-up Study) and more than 120,000 women (from the Nurses' Health Study) revealed some sobering statistics about weight and health. The volunteers provided their height and weight, as well as details on their diets, health habits, and medical histories. Researchers tracked the volunteers over more than 10 years, noting the occurrence of illnesses and comparing those developments with each subject's BMI.

Obesity increased the risk of diabetes 20 times and substantially boosted the risk of developing high blood pressure, heart disease, stroke, and gallstones. Among people who were overweight or obese, there was a direct relationship between BMI and risk: the higher the BMI, the higher the likelihood of disease.

Heart disease and stroke

Some of the most common problems seen in people who carry excess weight, such as high blood pressure and unhealthy levels of cholesterol and other fats in the blood, tend to occur together and may lead to concurrent health problems. For example, high blood pressure is about six times more common in people who have obesity than in those who are lean. Twenty-two pounds more weight boosts systolic blood pressure (the first number in a reading) by an average of 3 mm Hg and diastolic blood pressure (the second number) by an average of 2.3 mm Hg. These increases translate into a 12% increased risk of heart disease and a 24% increased risk of stroke, according to a 2006 statement from the American Heart Association. These numbers are important because heart disease is the leading cause of death in the United States and stroke ranks third.

Diabetes

Overweight and obesity are so closely linked to diabetes, experts have coined the term "diabesity" to describe the phenomenon. About 90% of people with type 2 diabetes (the most common form of the disease) are overweight or have obesity. The incidence of diabetes rose dramatically, by nearly 65%, between 1996 and 2006. High blood sugar levels, the hallmark of diabetes, are one of the features of metabolic syndrome (see below). Diabetes can't be cured, and if untreated or poorly controlled, it can lead to a number of grave health problems, including kidney failure, blindness, and foot or leg amputations. Diabetes is currently the sixth leading cause of death in the United States.

Do you have metabolic syndrome?

Metabolic syndrome, a cluster of conditions that occur together, also increases the risk of heart disease, stroke, and diabetes. One of the key features is abdominal obesity. If you have that problem, you're more likely to have the other characteristics.

You have metabolic syndrome if you have three or more of these five traits:

waist circumference higher than 35 inches in women or 40 inches in men

fasting blood triglyceride level of 150 milligrams/deciliter (mg/dL) or higher

HDL ("good") cholesterol of less than 40 mg/dL in men or less than 50 mg/dL in women

systolic blood pressure (the top number of a reading) of 130 mm Hg or higher, or diastolic (the lower number) of 85 mm Hg or higher

fasting blood sugar level of 100 mg/dL or higher.

(Note: You are considered to have a trait if you receive treatment for it, even if your numbers are normal with this treatment.)

Cancer

Obesity ranks as the second leading cause of cancer death, after cigarette smoking, some experts believe. A 2003 study by the American Cancer Society in the New England Journal of Medicine that followed more than 900,000 people for 16 years showed a link between excess body weight and many different cancers. Among people ages 50 and older, overweight and obesity may account for 14% of all cancer deaths in men and 20% of all cancer deaths in women. In both men and women, higher BMIs were associated with a higher risk of dying from cancer of the esophagus, colon and rectum, liver, gallbladder, pancreas, or kidney. In men, excess weight also increased the risk of dying from stomach or prostate cancer. In women, deaths from breast, uterus, cervix, or ovarian cancer were elevated in women with higher BMIs. Studies suggest that at least part of the problem may be because people who are very overweight are less likely to have cancer-screening tests such as Pap smears and mammograms. A 2005 report in the International Journal of Obesity showed that the larger the woman, the more likely she was to delay getting a pelvic exam, largely because of negative experiences with doctors and their office staff. In men, screening tests such as prostate exams may be physically difficult if people are very overweight, particularly if they tend to store fat in their hips, buttocks, or thighs.

Greater weight, shorter life?

Because excess weight plays a role in so many common and deadly diseases, overweight and obesity can cut years off your life. A study of more than one million adults showed that the lowest death rates were among men with a BMI of 23.5 to 24.9 and women with a BMI of 22 to 23.4. Severe obesity can lower life expectancy by an estimated 5 to 20 years, according to a 2005 report in the Journal of the American Medical Association .

In addition, several studies have hinted that low-calorie diets can slow the aging process. In one such study, published in 2006 in the American Journal of Cardiology, researchers compared heart function in people who ate restricted-calorie diets (between 1,400 and 2,000 calories per day) with people who ate typical Western diets (between 2,000 and 3,000 calories daily). They found that the hearts of the people who ate low-calorie diets were more elastic and resembled those of younger individuals.

Sleep apnea: Serious complications that start with snoring

If you snore loudly and temporarily stop breathing many times during the night, waking suddenly with a snort or choke, you probably have sleep apnea, another common disorder that's more prevalent with overweight and obesity. Your bedmate will probably notice these symptoms, while you may not. People with sleep apnea don't realize they've been awakened because they don't become fully conscious, but these awakenings can disrupt sleep. Not only does sleep apnea often lead to daytime sleepiness, it also increases the risk of high blood pressure, heart attack, and stroke.

Health benefits of weight loss

Losing excess weight can make you feel better both physically and emotionally and can help you live a longer, healthier life. Especially encouraging is the fact that you don't have to lose a tremendous amount of weight to become healthier. Even a modest weight loss of 5%–10% of your starting weight can lead to significant health benefits.

One major trial to show the benefits of lifestyle changes (including losing weight and exercising) was the Diabetes Prevention Program, published in the New England Journal of Medicine in 2002. It involved more than 3,200 people who were at risk for developing type 2 diabetes. Researchers found that people who lost just 7% of their weight and exercised about 30 minutes a day cut their risk of diabetes by nearly 60%.

Earlier, smaller studies offer additional evidence. In one, people with hypertension who lost a modest 10 pounds over 6 months reduced their systolic blood pressure by 2.8 mm Hg and their diastolic blood pressure by 2.5 mm Hg. These reductions in blood pressure were equivalent to the reductions brought about by treatment with blood pressure medications. Weight loss is so effective that many people with high blood pressure can stop taking blood pressure medicine after they lose weight, for as long as they are able to keep it off.

Review Date: 2006-09-01

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