Perhaps you've noticed them: the neighbor who uses walking lunges to get to the mailbox; the co-worker who sits on an exercise ball instead of a chair; or the family member who sprinkles ground flax seed on salads, cereal and ice cream.

They're all part of the burgeoning Stealth Health movement, a subtle but simple new wellness trend designed to sneak healthy behavior into the lives of time-pressed Americans.

Stealth Health involves taking nonthreatening baby steps to incorporate permanent, positive lifestyle change. It's blending silken tofu into cheesecake. It's pressing your forehead into your palms while sitting for an isometric neck stretcher and strengthener. It's deciphering labels and avoiding foods that contain trans-fatty acids or high-fructose corn syrup.

"We've long talked about the value of ounces of prevention, but with patients, that doesn't sound so light and easy. It sounds like a lot of work," said Dr. David Katz, a preventive-medicine specialist and director of Yale's Prevention Research Center. "We thought, 'What if we carved (good health habits) into tiny pieces and let people slip them into their lives one bit at a time?' "

That germ of an idea sprouted into a comprehensive 415-page preventive-medicine bible by Katz and health writer Debra Gordon. The guide, called "Stealth Health: How to Sneak Age-Defying, Disease-Fighting Habits Into Your Life Without Really Trying" (Reader's Digest, $14.95 paper), contains more than 2,400 easy lifestyle tweaks designed to "work health into the nooks and crannies of your life."

At a time when the government's new dietary guidelines call for us to eat more vegetables than in the past — 2 1/2 cups a day — and exercise up to 90 minutes a day to lose weight, we need all the inspiration and time-saving tips we can get.

The idea behind Stealth Health is to pick three new strategies and try them for four days in a row. Once a new behavior has become a regular part of the day, even if it's something as small as drinking a glass of water first thing in the morning, participants add another.

Registered dietitian Evelyn Tribole first popularized the concept in her 1998 book "Stealth Health: How to Sneak Nutrition Painlessly Into Your Diet" (Viking, $24.95).

Tribole not only gives tips on how to slip more fiber, beans, soy, calcium, fruits and vegetables into a diet, but she also includes more than 100 recipes that address what she calls the major stumbling blocks to good nutrition: flavor, convenience and prejudice.

To sneak vegetables into meals, for example, she suggests pureeing cauliflower and adding it to twice-baked potatoes. Drop bits of a grated carrot into cheddar chowder or spaghetti sauce. Or spice food up with chilies, garlic and ginger.

"People want to eat healthy, but there's a preconceived bias that healthy food tastes bad," she said. The mere mention of tofu often evokes a disdainful look. "Yet if I make a delicious chocolate marble cheesecake (with tofu) and have a person taste it (without mentioning the ingredients), I get raves," she wrote.

Gordon and Katz devote an entire section to Stealth Healthy Cooking, which includes tips on how to cut back on "bad" carbs, sugar, bad fats and salt. But they also weave nutritional nuggets throughout the chapters. They tell you how to survive dining out at full-service and fast-food restaurants, what to eat for healthy skin (soy isoflavones found in soy milk and tofu) and the numerous benefits of omega-3 fatty acids.

Stealth Health preaches that small changes add up to a large difference. In the current environment, where junk food is encouraged and regular movement is discouraged, it's impossible to stay healthy by maintaining the status quo. Good health requires proactive measures every day.