Kidney stones may be tiny, but they can cause intense pain. If you've ever had a kidney stone, you're probably willing to try whatever it takes to guarantee there won't be a repeat performance. Fortunately, you may be able to affect your risk of developing kidney stones by losing weight. Although all the evidence isn't yet in, obesity may contribute to your risk, and losing weight may reduce that risk.
Background
Your kidneys filter debris and impurities from your blood and eliminate them from your body in your urine. Kidney stones develop when minerals in your urine crystallize in your urinary tract. Most pass from your body without medical intervention, but they can be excruciatingly painful as they move down your urinary tract and out in your urine. It's not clear why some people get kidney stones while others do not, although men are more likely to suffer from them than women.
Obesity
Obesity seems to be a risk factor for kidney stones. Harvard University professor Dr. Eric Taylor studied men and women over 20 years, comparing their risk of kidney stones and their weight. He found that the heaviest women face an 89 percent greater risk of kidney stones than the lightest women and that the heaviest men face a 44 percent greater risk when compared with the lightest men. In addition, gaining significant weight as an adult also raised people's risks of kidney stones.
Recommendations
Researchers at the University of Texas Southwestern Medical Center also say they've found an increased risk of kidney stones in fatter people. Therefore, physicians at the center recommend to overweight and obese patients that they lose weight because it may reduce their risk of repeat bouts with kidney stones. However, they note that studies haven't yet definitively proven that losing weight helps reduce your risk of kidney stones.
Considerations
There's some evidence that one weight-loss strategy -- gastric bypass surgery -- may actually increase your risk of kidney stones. In another research project from UT-Southwestern Medical Center, clinicians analyzed the urine of obese people who had the surgery and found that the surgery increased the concentration of certain substances that indicate a raised risk of kidney stone formation. Although kidney stones might not form for months or even years following the surgery, patients and their physicians need to recognize the risk, the researchers concluded.
References
- National Kidney and Urological Diseases Information Clearinghouse; Kidney Stones in Adults; October 2007
- UT-Southwestern Medical Center; Excess Body Weight Linked to Formation of Uric Acid Kidney Stones; March 2004
- Harvard University; Weight Gain and Obesity Linked to Higher Risk of Kidney Stones; January 2005
- UT-Southwestern Medical Center; Gastric Bypass Surgery Increases Risk of Kidney Stones; March 2010
