For years, Brenda Kovacs has been head cafeteria worker for Quaker Valley Middle School in Sewickley, Pa., but her job isn't the same as it was a few months ago.

As usual, she arrives at 8 a.m. to prepare meals for 150 youngsters. But these days, she has even more to do before the first lunch at 10:07 a.m.

On a recent "Taco Tuesday," she chopped fresh romaine lettuce, stirred two stainless steel pots of brown rice and sliced baked potatoes. An hour later, she served corn with one hand and gestured to a selection of fresh fruit with the other.

"Try that salsa! And I want to see a fruit," Kovacs said to the seventh- and eighth-graders filling their trays.

This school year, following new federal school lunch regulations that took effect in July, school districts around the country are taking on simultaneous roles of chefs, salespeople and amateur food designers.

The U.S. Department of Agriculture announced the new school lunch regulations in January. Food-service directors at schools participating in the federally subsidized National School Lunch Program spent much of the summer crafting menus to accommodate the changes.

That includes planning meals that eliminate trans fat, reduce sodium content and offer more whole grains, fruits and vegetables. Students now must take a fruit and a vegetable at lunch.

There are more specific rules, too. Schools must offer nine to 12 whole grain options for high school students. Meals must fall within a specified 100-calorie range -- 750 to 850 calories at high schools, for example.

Not all students will be receptive to the changes, of course, but food-service directors said they're trying to serve them as customers, not just consumers. So now food-service workers have to think seriously about display.

Before school started, Quaker Valley food-service director Jennifer Reiser called all of her cafeteria workers together for a four-hour PowerPoint presentation called "Back To School Dining Boot Camp 2012." She covered just about everything -- including why the way they display Doritos matters.

"Make it look like they are eating in their favorite cafe!" slide No. 75 exclaims in red letters, with a photo of baked chips neatly arranged on a shelf.

Sure enough, it looks like a selection you would find in a Subway shop.

Reiser stopped by on "Taco Tuesday" and, without a recipe, showed her staff that sometimes it takes only a little extra time to make some foods from scratch.

"I'm just kind of winging it, honestly," she said, stirring the mix with gloved hands.

At first, her salsa of black beans, fresh tomatoes, corn, seasoning and lime was not a big hit. But by the end of the day, only a few cups were left.

Samantha Hiller is the self-described "fruit chick."

She sliced up kiwi and strawberries and arranged them neatly with grapes in black plastic containers. Many schools are using the black containers since the new regulations took effect because the fruit looks more vibrant against the dark background and the container holds one portion of fruit.

Although no rule dictates how cafeteria workers should display food, the requirement that students select a fruit option is sparking conversations about what will best appeal to them. Kovacs suggested sliced pineapples with a blueberry in the center to resemble a flower.