Researchers have found yet another reason for people to watch their weight: kidney failure.

A University of California at San Francisco study released on Monday found a strong relationship between obesity and end-stage renal disease, or kidney failure.

“There are more and more people with kidney failure, but it hasn’t been appreciated much that kidney failure can be a consequence of obesity,” said Dr. Chi-yuan Hsu, an assistant professor of medicine and lead author of the study.

Even moderately overweight people had a higher risk of kidney failure than people whose weight was in a normal, healthy range, he said. And for the morbidly obese, the risk was more than 700 percent greater, Hsu said.

When the kidneys fail, and cannot process waste and excess fluid, the patient requires dialysis or transplantation.

The study, conducted jointly with Kaiser Permanente of Northern California Division of Research and supported by the National Institutes of Health, will be published in the Jan. 3 issue of the Annals of Internal Medicine.

The research is based on data from more than 320,000 Northern California Kaiser members whose height and weight were tracked between 1964 and 1985. A total of 1,471 cases of end-stage renal disease occurred among study participants during an average follow-up period of about 26 years.

Being obese or overweight was seen as a risk factor even after the researchers adjusted for high blood pressure and diabetes, other known risk factors, Hsu said.