Now Hear This. And That, Too.

Since the first book's publication, Zinczenko says, several of the restaurants whose menus took a hit in its pages have contacted him with pledges to reform their ways. Many, he says, have dropped items from their menus, and others have changed their recipes to make them more nutritionally palatable. Some of the best-selling foods on chain restaurants' menus have been removed or altered, he says, and individual products have been improved, too.

For instance, Zinczenko notes, the main line of Capri Sun juice pouches has been reformulated with 25 percent less sugar. "The biggest food purveyors in the country are updating their menus and reaching out to us for guidance," Zinczenko says.

Now Zinczenko and Goulding, whose ETNT! franchise includes a hugely popular blog on Yahoo and a twice-weekly e-mail newsletter, are taking that fight to the supermarket. But here the pressure's not so much on manufacturers to change their products as on consumers to pause before they buy.

"If this book gets you to stop and think about what you're putting in your body, you're going to lose weight," Goulding says. "It's an education campaign on our end."

The book walks you through the produce, meat and dairy sections -- the perimeter of the grocery store, where you'll find the freshest, least processed foods -- doling out insights and advice. Those claims -- "all natural," "no growth stimulants or added hormones," "organic" and the like -- that you find on packages of meat and chicken? Zinczenko and Goulding translate them for you: "All natural," for instance, is "all but meaningless to the consumer" because the government doesn't carefully regulate the term's use.

In the produce section, we learn that "beautiful doesn't mean delicious," and we get an illustrated primer on choosing the best fruit and vegetables. "Shop with the seasons," the authors suggest; doing so is "cheaper, it's better, and it's better for you."

Because it can't possibly comment on each of the, by their count, 50,000 items in the typical supermarket, the book moves beyond specifics to offer broader guidelines and techniques for making your own intelligent choices. A "snack matrix" shows how to pair up dozens of individual snack items to create 200-calorie snacks; they're all healthful and tasty alternatives to 100-calorie snack packs (which everybody eats two of, anyway).

Similarly, a "beverage label decoder" sorts through common claims found on soft-drink and juice bottles. Hint: "All natural" has little meaning here, either.

The supermarket guide, like the previous two books, offers a handful of healthful recipes (complete with shopping lists) plus handy tips throughout. Use canola instead of olive oil for dressing salads and cooking, the guys advise: It costs about a quarter of what you pay for olive oil, and it "happens to have an even better ratio of monounsaturated fat to saturated fat than the vaunted extra virgin." Similarly, the authors advise that you swap your ketchup for salsa, which is "more nutritious . . . and twice as versatile."

When it comes to comparing snack crackers, cereals, breads and other processed foods from the center aisles, distinctions are sometimes a bit murky, and caveats abound: On the sweet cereals pages, for instance, a tiny note reads, "None of these cereals are ideal for daily consumption, but if you must have sugary stuff in your pantry, stick to this page." Apple Jacks and Froot Loops come out on top of this dubious pack: "In the world of sugary cereals," the book notes, Froot Loops -- with 110 calories, one gram of fat and 12 grams of sugar per cup -- are "a surprisingly sober pick."

The "Eat This, Not That!" books are compact but a bit too heavy to carry around in your purse; too bad, because I'm certainly tempted to take mine to the grocery store. (Luckily, you can arrange to subscribe to a mobile version at http://www.eatthis.com; you can also sign up there for the free weekly ETNT! newsletter.) Still, I keep my copy handy while making my weekly shopping list.

And I don't feel bossed around at all.

Check out today's Checkup blog post, in which Jennifer reports on how lack of sleep can affect the common cold. Subscribe to the weekly Lean & Fit nutrition newsletter by going to http://www.washingtonpost.com and searching for "newsletters." Go to the Wednesday Food section to find Nourish, a new feature with a recipe for healthy eating every week. And e-mail your thoughts to Jennifer at checkup@washpost.com.