Obesity surgery has helped many patients lose weight and improve their health, a panel of experts told U.S. regulators on Thursday, but they added there was insufficient data on how well the procedure worked for elderly patients covered by Medicare.

The Centers for Medicare and Medicaid Services (CMS) is considering whether the government’s health insurance plan for the elderly and disabled should pay for the surgery, which shrinks the stomach with either a removable band or by physically removing part of it.

“I didn’t see any data whatsoever that these very same results could be applied” to Medicare patients, said Barbara McNeil, panel vice chairwoman and head of health-care policy at Harvard Medical School.

Regulations limit CMS coverage to defined diseases, but earlier this year the agency deleted language that said Obesity was not a disease. The agency can now consider paying for obesity-related therapies, including surgery.

The panelists’ advice is not binding but will help CMS officials decide whether to change how it pays for the procedure. The agency already covers some surgeries to alleviate serious obesity-related conditions like diabetes, but coverage varies among regions.

Private health insurers, who often eye Medicare coverage decisions when formulating their own, have been growing more skeptical of such surgeries, some experts have said.

A number of companies make devices or parts used in the surgery, including Inamed Corp., International Ltd. and Synovis Life Technologies Inc. Johnson & Johnson also makes stomach bands used in Europe.

Weight problems are a growing health issue in the United States, where nearly two-thirds of adults are overweight or obese, according to the National Institutes of Health.

Obesity is defined as having a body mass index (BMI) - a weight-for-height - of more than 30. For an average woman, that usually means being 30 pounds overweight and, for an average man, 35 to 40 pounds.