For millions of American women, dieting is a way of life. At any given time, more than a third are trying to lose weight. Many will repeatedly lose a few pounds, only to regain the weight later -- a pattern known as yo-yo dieting or weight cycling. Unfortunately, this up-and-down approach is more than just frustrating. It may actually put women at increased risk for gallbladder disease.

Doctors have known for years that obesity ups the odds for gallstones, as does the quick shedding of pounds. But new evidence suggests that weight cycling itself, regardless of obesity and the pace of weight loss, is also a risk factor. A 22-year study involving more than 47,000 women, published recently in the journal Annals of Internal Medicine, found that those reporting at least one episode of weight cycling greatly increased their risk for gallstones. Moderate weight cycling, involving 10 to 19 pounds, raised a woman's risk of gallstones by 31 percent, while severe cycling of 20 or more pounds upped her odds by 68 percent.

"Obesity is one of the strongest risk factors for developing gallstones," says the study's lead author, Dr. Sapna Syngal. "Weight fluctuation [is] an additional risk." Besides being extremely painful, gallstones can lead to serious health problems and often require surgery -- one more incentive for women to find a healthy approach to weight management.

Women, weight, and gallstones

A small pear-shaped sac, the gallbladder stores bile, a fluid produced by the liver that helps the body digest fat. During digestion, the gallbladder contracts, releasing its contents into the small intestine. If cholesterol or other elements are out of balance or if the gallbladder does not completely and regularly empty, bile can thicken and form one or multiple stones, varying in size from a grain of sand to a golf ball.

Women are susceptible to gallstones due to hormonal fluctuations -- estrogen changes bile composition and decreases gallbladder movement. For women who are dieting, the risk of developing gallstones is even greater.

"With weight loss, the liver tends to pick up more cholesterol from the blood and put it out into the bile. That increases the risk of gallstones forming," says Dr. James Everhart, of the National Institutes of Health. "The other mechanism concerns the contraction and cleansing of the gallbladder after meals. If one doesn't eat often or eats a nonfat or low-protein meal, the gallbladder won't contract. That gives more time for cholesterol and other materials in the bile to settle and form gallstones."

Symptoms and treatment

Every year, about 1 million Americans learn they have gallbladder disease. While some people with gallstones do not experience symptoms and require no intervention, many experience severe pain. A sudden, steady abdominal pain lasting from 15 minutes to several hours is the typical sign that a gallstone has blocked the duct that carries the bile out of the gallbladder. Pain might occur in the right shoulder or between the shoulder blades. Patients may feel nauseated, vomit, or suffer from gas and indigestion. Several weeks, or even years, may pass between "attacks."

Since gallstone symptoms often mimic a heart attack or other serious conditions, sufferers should seek medical attention for an accurate diagnosis. Prolonged duct blockage with persistent pain, fever, or yellowing of the skin and eyes can cause serious complications and requires medical attention.

Treatment for gallstones generally consists of removing the gallbladder during a traditional or laparoscopic surgery. For a small number of patients, doctors prescribe a medication called ursodiol (Actigall), which dissolves some small stones and may prevent gallstone formation. About half the patients treated nonsurgically, however, develop more stones. Moreover, ursodiol is not generally recommended for dieters.

Safer weight management

To maintain a healthy body weight, both Dr. Syngal and Dr. Everhart suggest that women make lifestyle changes.

"Slower weight loss is better, and that's not just true for gallstones. It's recommended anyway. A slow, steady weight loss is more likely to be sustained and safer than weight loss obtained through severe calorie restriction," Dr. Everhart concludes. "And there's epidemiological research showing that increased physical activity decreases the risk of gallstones. Weight loss that incorporates physical activity might decrease the gallstone risk."

For those wanting to slim down the healthy way, discipline and moderation are the keys. There's not a diet in the world that beats regular, balanced meals and plenty of exercise.

Related links:

Rx.magazine feature story: Making Exercise Work for You

Outside link: Information on dieting and gallstones from the National Institute of Diabetes and Digestive and Kidney Diseases (part of the National Institutes of Health)

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