The average American may be growing fatter, but not for lack of information on getting thin.

The average American may be growing fatter, but not for lack of information on getting thin.

New diet and exercise books seem to appear daily: In 2006 alone, 2,215 new health and fitness titles were published, according to R.R. Bowker's Books In Print, which tracks publishing industry information. That's only a slight drop from 2005 (2,475 new titles) and 2004 (2,523 new titles).

It adds up to a marketplace filled with advice on shedding pounds and building muscles.

Here's a roundup of some new titles that aim to inspire this summer:

"Extreme Fat Smash Diet" by Dr. Ian K. Smith (St. Martin's Griffin, $13.95).

Promise: Lose 12 pounds in three weeks.

Method: This update to last year's best-selling "The Fat Smash Diet" (still a top seller on Amazon.com) offers three weeklong cycles of detailed meals. It preaches the benefits of cardio workouts, small portions and a food journal.

Dieters are divided into groups: those who lose weight easily, those with more trouble and those who can't seem to drop a pound. The writing is accessible, but cloying metaphors abound ("I like to think of metabolism as a car's engine transplanted into your body...").

"The Cardio-Free Diet" by Jim Karas (Simon Spotlight Entertainment, $23) .

Promise: Lose weight within two weeks by exercising for a total of two hours.

Method: "Cardio kills," writes Karas. "It kills your weight loss plan, your joints, your immune system, your body composition, your time, and, most of all, your motivation." Instead, he prescribes a strict regimen of strength training (bicep curls, lunges, squats, etc.) to increase muscle mass and kickstart metabolism, thus burning calories.

With an almost angry edge, Karas talks of "inhibiting protein synthesis" and "elevated troponin levels," and suggests you buy "SPRI exercise tubing." High-tech as it sounds, his message is one you've heard since junior high gym class: Eat less and exercise more.

"The Abs Diet for Women: The Six-Week Plan to Flatten Your Belly and Firm Up Your Body For Life," by David Zinczenko (Rodale, $24.95).

Promise: It's all in the subtitle — sexy abs in six weeks.

Method: This fourth book in the "Abs Diet" series is aimed at women. By burning belly fat, Zinczenko says, you'll protect your heart, look fabulous and have better sex.

Portion sizes for the six high-fiber, high-protein daily meals are determined by the dieter, and the strength training workout includes optional cardio. Zinczenko offers "powerfood" recipes (which sound reasonably tasty), tips on shopping for produce and a "special bonus section" on psychological strategies.

Motivational style: Down-to-earth, well-informed friend, with occasional Richard Simmons-like outbursts. "Most diet plans portray snacking as a failure," he writes. "I want you to think of snacking as exactly the opposite — as a key to success!"

"Bikini Bootcamp: Two Weeks to Your Ultimate Beach Body," by Melissa Perlman and Erica Gragg (Broadway, $17.95).

Promise: 14 days of intense workout, fruit-and-veggie meals and good thoughts will get you beach-ready.

Why people might listen: Perlman and Gragg run Mexico's Amansala Spa, where vacationers at the real-life Bikini Bootcamp get shaped-up under the sun.

Method: If you commit to this bootcamp, there may not be room in your life for much else.

You're told to do more than two hours of exercise each day, plus prepare meals according to their recipes. With that much work, it's easy to believe you'll see some results.

The workout includes strength training, cardio (in the form of walking) and yoga. The recipes sound delicious and there are grocery shopping lists included.

But the book's selling point is its attempt to channel the healing experience of a spa. There's much talk of meditation, journal writing and internal healing, and readers can whip up the recommended mud masks and hair treatments for spa-like pampering.

Motivational style: Pep talks from your new-agey best girlfriend, which sometimes get a bit epic: "Many people on our program feel as though their entire body 'wakes up,' so great is their newfound vigor and clarity."