"Obesity is medically accepted to be a disease in its own right," the IRS said.
Taxpayers who participate in these programs for medically valid reasons will now be able to deduct amounts above 7.5 percent of their adjusted gross income, similar to any other medical expense not covered by insurance or other reimbursement. A taxpayer's spouse and dependents would also be covered.
Still not deductible, however, are the costs of weight control programs intended "to improve the taxpayer's appearance, general health and sense of well-being."
Diet foods also are not be deductible, even though they are often an integral part of a weight control program under a physician's supervision. The IRS reasons that people have to pay for food whether or not they are trying to lose weight.
Fees, diet menus and literature and other costs would be deductible.
The IRS has previously permitted deductions for weight-loss programs recommended by a physician for treatment of a disease such as high blood pressure. But the agency has never specifically cited obesity itself as a disease.
The American Obesity Association estimates that 39 million Americans are obese, causing 300,000 unnecessary deaths in the United States each year.
The ruling applies not only to 2001 income tax returns - which are due April 15 in most of the country - but as far back as 1998. Taxpayers who want to take the deduction need only file an amended return for the tax year in question.
The IRS also recently included smoking cessation programs as deductible medical expenses, as are treatment and other costs for alcoholism.
By Curt Anderson