The signs are up, the brochures are out and the commercials have been filmed.

The new McLean Deluxe Sandwich - a 91 percent fat-free hamburger patty on a sesame seed bun - awaits only the beginning of a media blitz later this month to trumpet its arrival.But many Salt Lakers didn't need TV commercials to tell them the McLean had come to town. Customers at the McDonald's in Crossroads Plaza had been asking for the new hamburger for the past two weeks, said Karen Baessler, manager.

The hamburger, available at most Salt Lake McDonald's outlets for the first time Tuesday, made an impressive showing its first day out. The lunch crowd at the McDonald's on 210 W. 500 South ordered 89 of the burgers Tuesday. Crossroads' crowd bought 89. The hamburger, which eschews mayonnaise, will be available nationwide by the end of the month.

Gareth Mark is a regular customer at the Crossroads restaurant and a longtime fan of the Big Mac. Wednesday he switched. After finishing his first McLean, Mark said it tasted as good as the Big Mac. "I didn't particularly notice that it was fat-free." He plans to order it regularly in the future. "Why not? It's healthier."

Chris McKay, owner of the McDonald's on 500 South, is grateful the national McLean ad campaign won't begin until April 19. That gives her time to teach her cooks the finer points of making the leaner burger.

"You don't want it to stay on the grill even a second longer than it should because it will dry out," she said. The McLean burger, which replaces the McDLT, has 320 calories and 10 grams of fat. "I can feel real good about that," said McKay.

So can her customers. "We talked to a lot of the ones who ordered the McLean today, and we didn't have any say they wouldn't order it again," she said.

McKay's informal survey included an 11-year-old boy who said he liked the McLean better than the Big Mac, she boasted.

The McLean burger plays a key role in McDonald's aggressive wooing of the health-conscious consumer. Although the chain has offered salads for years, only this week could it claim that its trademark food - that uniquely American hamburger - is good for you.

The hamburger's low-fat content makes it less moist than traditional hamburgers, but there is no noticeable difference in taste. In keeping with its low-fat purpose, the hamburger comes with catsup, mustard, pickles and onions. If you are willing to take on an extra three grams of fat, you can order one with cheese.

The McLean's debut comes hard on the heels of other McDonald's improvements. Milk shakes are now 99.5 percent fat-free, made with skim milk. Deep-fat fried food (including fish and chicken products and french fries) are now fried in 100 percent, cholesterol-free vegetable oil. The chain claims a small order of fries has only 2.5 grams of fat per serving. In many places, ice cream has been replaced with lowfat yogurt and the chain's breakfast menu features no-fat, no-cholesterol muffins.

In the old days, a fast-food junkie couldn't eat at McDonald's three times a day and stay within sound nutritional guidelines, McKay said. "Now you can!" she announced.

With these kinds of changes, the chain's mascot - the undeniably fat Ronald McDonald - seems like a relic of bygone excesses. The new, health-conscious McDonald's needs a clown with biceps and a 30-inch waist.