WASHINGTON - A federal judge has dismissed claims by parents from Bronx, N.Y., that their children became fat and developed high blood pressure and diabetes because they frequently ate fast food from McDonald's.

U.S. District Court Judge Robert Sweet, tossing out the suit yesterday in his 65-page opinion, said McDonald's patrons either know or should know that overindulgence in Big Macs and Chicken McNuggets could cause health problems.

Therefore, he wrote, it is their own fault if consumers "nonetheless choose to satiate their appetite with a surfeit of supersized McDonald's products."

Legal analysts and health-food advocates had watched the case closely as a test of whether product-liability strategies employed successfully against tobacco companies could be used against fast-food giants such as McDonald's that help fuel the nation's expanding waistline.

The judge's ruling in this first-ever case made it clear that, for now, the answer is "no."

McDonald's makes no secret of the fat and cholesterol levels of its products, Sweet noted, with such information available on the company's Web site and on posters in retail outlets.

For those who choose to patronize McDonald's, "it is not the place of the law to protect them from their own excesses," Sweet wrote.

"Nobody is forced to eat at McDonald's, except perhaps parents of small children who desire McDonald's food, toy promotions or playgrounds and demand their parents' accompaniment. Even more pertinent, nobody is forced to supersize their meal or choose less healthy options on the menu."