Frugality is the new black. Throw in the terms "eco-friendly" and "healthier," and the result is a trifecta of hip.

Who knew packing a lunch could symbolize so much?

"It's every penny counts," says Kevin Wehr, an assistant professor of sociology at California State University, Sacramento. "It's expensive to go out to eat, and when people have fewer dollars in their pockets, it's a cheap and easy way to reduce expenses."

American adults carried 8.5 billion lunches from home in 2007, the most recent figure available, according to the NPD Group consumer market research firm. More than half were eaten at work, mostly right there on top of desks. And although sandwiches are still the most-packed item — 40 percent of lunches include them — there are easy ways to keep lunch from being the old standby PB&J.

"There's no question Americans are carrying more lunches from their homes than they were at the beginning of this decade," says Harry Balzer, NPD Group vice president. "It's the cheapest way to feed ourselves."

Matt Robinson has been taking food to his job as a legislative analyst at the California Department of Fish & Game for the past four years.

"I started realizing that I was going to La Bou and spending $10 a day on a sandwich and chips, and that I can buy an entire week's worth of lunches (for the price of one day) if I just went to the store," the 30-year-old says.

Robinson keeps it interesting by switching up what he buys at the supermarket each week — he'll choose different sandwich meats and cheeses, and he varies his bread to include pitas and wraps.

"I pack the exact same thing for an entire week," he says, rounding out the meal with fruit, vegetables and chips.

And while he saves money by bringing his own food, he also uses his regular lunch break to work out at the gym nearby.

Carrie Person of Roseville, Calif., packs a thermal-insulated case of food for her husband, a software salesman, every night before going to bed.

"He leaves for work really early," she explains.

Person, 33, varies yogurt flavors, sandwich meats, breads, even mustards, she says. Her husband used to be chastised for being a frugal foodie in the office, but he now looks like something of a trendsetter.

"His co-workers used to tease him about bringing his lunch," Person says. "Now, a lot of them are starting to do it as well."

Speedy lunch

Packing a lunch doesn't have to be a time-consuming process, says Deborah Hamilton, who writes the blog www.lunchinabox.net.

Hamilton sends a bento-box lunch to school with her son every day.

"I would like to say I have a master plan and my evil genius of bento kung fu tells me what to do, but really it's whatever I have in the house," she says. "I try not to spend more than 10 to 15 minutes on any one bento because I have a kid I'm getting ready in the morning."

A bento box is simply a reusable container that encourages the packing of a variety of foods with a basic five-color rule — include at least five colors in each box. Hamilton likes using an assortment of containers she purchases for just a few dollars each because they automatically result in portion control.

If a box is packed using a general guideline of three parts carbohydrates to one part protein and two parts fruits and vegetables, the calories contained are usually relative to the size of the box — so a 600-milliliter box carries about 600 calories, she says.

And there's nothing that cannot go into a bento, even though it has Japanese origins.

"I have culinary (attention deficit disorder), and I can't stick to one particular ethnic group or food," Hamilton says. "So I bop all over the map, based on what I'm making for dinner."

Leftovers often go inside, and Hamilton also keeps three bins — one in the refrigerator, another in the freezer and a third in the pantry — with items that can be thrown into a box. She calls these "gap-fillers."

The refrigerator bin includes single-serving cheeses, hard-boiled eggs, grapes, cherry tomatoes and vegetables that can be quickly microwaved in a mini-steamer. The freezer bin holds pre-made rice balls, leftovers frozen in reusable muffin cups, mini-frittatas, and mini-hamburgers she made with leftover dinner meat. And the pantry bin has puddings, nuts and crackers.

As far as food safety is concerned, her son does not have access to a microwave or refrigerator, so she includes frozen fruit or juice that serves as an ice pack but also melts by lunchtime.

"You can make it really Martha (Stewart) if you want to," she says. "But it really doesn't have to be."

8 ounces pasta1 cup broccoli, cut into bite-size pieces1½ cups green beans, sugar snap peas, cabbage or zucchini, cut into bite-size pieces¾ cup carrots, cut into thin 1-inch strips1 clove minced garlic (optional)2 tablespoons sesame oil2 tablespoons soy sauce2 tablespoons sesame seeds2 tablespoons fresh cilantro, chopped½ cup bean sproutsBoil pasta in large pot of boiling water until it is half cooked. Add all vegetables, except bean sprouts, and boil until pasta is al dente and vegetables are tender.Drain and place in large bowl.Mix together garlic (if using), sesame oil and soy sauce for dressing.Add the sesame seeds, cilantro, bean sprouts and dressing to the pasta. Toss well.Recipe from "The Laptop Lunch" by Amy Hemmert and Tammy Pelstring.

4 cups diced cooked chicken,1 stalk celery, cut into ¼-inch dice4 scallions, trimmed and thinly sliced, or ¼ cup sweet onion cut into ¼-inch dice1½teaspoons finely chopped fresh tarragon or fresh dill2 tablespoons finely chopped parsley1 cup prepared or homemade mayonnaise2 teaspoons strained, freshly squeezed lemon juice1 teaspoon Dijon mustard2 teaspoons kosher saltFreshly ground black pepperIn a mixing bowl, toss together chicken, celery, scallions and herbs. Set aside.In a small bowl, whisk together mayonnaise, lemon juice, mustard, salt and pepper to taste. Add to the chicken and mix gently until combined.Serve on a bed of lettuce with sliced tomatoes in half an avocado, or in a chicken club sandwich made with bread, bacon, tomatoes and lettuce.Recipe by Food Network Kitchens.

1 tablespoon fat-free cream cheese1½ teaspoons fat-free ranch dressing1 10-inch wheat tortilla2 tablespoons broccoli, cooked or raw, finely chopped2 tablespoons carrots, finely shreddedStir ranch dressing into cream cheese. Spread mixture within ¼ inch of entire edge of tortilla.In a bowl, mix broccoli, carrots and optional ingredients such as 1½ teaspoons sunflower seeds; 1 tablespoon sun-dried tomatoes packed in oil, patted dry and finely chopped; 1½ teaspoons golden raisins; 1 tablespoon water chestnuts, chopped; or 1 tablespoon mango chutney. Sprinkle a thin layer of mixture on tortilla within ¼ inch of edge. Roll up; pin with toothpicks. Chill at least 2 hours. Slice into pinwheels 1 inch thick.Recipe from "The Healthy Lunchbox" by Marie McClendon and Cristy Shauck.