Tim Firnstahl owns restaurants. Von’s Grand City Cafe, the Kirkland Roaster & Ale House, Sharps Roaster & Ale House. For years, in partnership with fellow Islander Mick McHugh, he also ran such eateries as Jake O’Shaughnessey’s and F.X. McRory’s Steak, Chop and Oyster House.

Tim Firnstahl must be a meaty, manly kind of guy.

Tim Firnstahl also writes books. Well, two. His first was a cookbook on sourdough. His second, the just-published BodyRenewal, is a how-to compendium of diet, exercise and psychology that Firnstahl has spent 17 years researching and developing.

On the book’s cover is a photograph of Firnstahl, lording it over Time (represented by a clock face) and doing an excellent imitation of Charles Atlas. Inside the book’s cover are nearly 400 pages of advice, diagrams, recipes and statistics, laced with such shibboleths as NeoCuisine (Firnstahl’s recipes) and Macro Deflexions (Firnstahl’s stretching exercises) and Control Psychology (Firnstahl’s concept that “beliefs affect feelings”).

Tim Firnstahl must be a New Agey, health-nutty kind of guy.

Of course, Firnstahl is both, and neither, of those kinds of guys. Yes, he admits, he does run “all these hedonistic meathouses,” but he insists he doesn’t eat at them on a daily basis. And yes, he did pose shirtless for his new book, but that’s only because he believes that readers need to know the author practices what he preaches.

In fact, Firnstahl lives what his book espouses: moderation. He works out six days a week, but “working out” means dumbbells and rapid walking, not Nautilus machines and marathon running. For lunch last week, he fed happy Reporter staff a hearty meal of clam chowder and Caesar salad (NeoCuisine versions, naturally) instead of wheatgrass and granola. And he proudly wore a shirt from one of his artery-clogging restaurants while cooking his heart-healthy meal.

After all, going barechested can get chilly at times.

“From age 40 to 50, I put on a pound a year,” says Firnstahl. “I tried all these diets, I read everything, I subscribed to every magazine. At age 50, I looked back and said, ‘This is nuts! There’s gotta be a better way.”’

So Firnstahl, who is now 57, began reshuffling all the information he’d learned about diet and exercise, and combined it with his restaurant experience in inventing recipes and his business background in organizational psychology.

“Everybody knows to diet and exercise, right?” he asks rhetorically. “But the problem with all the books I tried was that they weren’t holistic. They didn’t include all the arenas: diet, exercise and psychology. And the arena where diets always fall apart is the long-term reinforcement.”

In other words, you can starve and sprint all you want, but if you don’t keep at it – and, more importantly, if you don’t enlist your spouse, your family and your friends to help you out – you’re doomed.

“If you don’t get your spouse’s approval, it won’t work,” nods Firnstahl.

Firnstahl’s spouse, Merriann, clearly approves of her husband’s system. She admits that she doesn’t plan every meal around her husband’s recipes, but she waxes enthusiastic about them, about the exercise plan, about the whole deal.

“And Tim, he’s 100 percent,” she smiles.

He serves up bowls of clam chowder, warning not to judge until after the third bite, when the palate has grown accustomed to the taste. She brushes him off, declaring, “I always judge on the first bite!” And digs in.

“What you’re eating today is everyday food,” Firnstahl says. “Not the best clam chowder you’ll ever eat, but you’ll say, ‘Hey, this is tasty, I could eat this every day.’ And by the third bite, your palate will be saying, ‘This is great! I love this!’ You’ll be singing!”

Firnstahl’s restaurants, his pragmatic wife points out, all have low-fat options on their menus. Firnstahl himself says he thinks of the restaurants as “special-occasion locations,” as places where you go for an occasional splurge. If he does eat out, he usually orders between the lines: lobster with no butter, extra orders of vegetables, a salad that he dresses with his own vinaigrette.

“But I’m not a monk!” he insists.

In his family, Firnstahl represents the fourth generation to go into food as a career. His great-grandfather was a cheesemaker in Wisconsin. His grandfather started the Sunny Jim food products company; his father ran it.

As for himself, Firnstahl says, “I’m not a very good dancer, and I have no affinity for brain surgery.”

He majored in finance at the University of Santa Clara, served in Vietnam, earned an MBA from Harvard Business School and got a master’s in organizational psychology. In between, he ran a variety of restaurants, including a combination hotel-restaurant in Bellevue where he met Merriann, a teacher working temporarily as a waitress.

“My life is flavor,” Firnstahl declares.

He credits his “poor wife” for having the patience to taste-test every version of every recipe that went into his book, and he expresses his gratitude to Better Than Bouillon, a company that makes concentrated meat flavorings.

“QFC will order it for you,” Firnstahl reveals. “It’s great. That’s one of the hardest things I’ve ever had to learn in the culinary arts: cooking without fat that still tastes good.”

“Don’t beat yourself up for being overweight,” Firnstahl counsels. “It’s the fault of the environment, and of time.”

“Environment” is the American way: sitting all day, driving everywhere. “Time” is the past 150 years or so, when modern transport, refrigeration and hothouses made the same foods readily available all year round. We eat, we sit, we get fat.

“In China, Europe, there’s much more walking and biking,” says Firnstahl. “We just don’t move enough.”

To that end, Firnstahl developed his own exercise plan, laid out in BodyRenewal as a series covering strength, endurance, balance and flexibility, built around a workout plan that’s no more strenuous than striding on a regular basis.

“If you walk at a pace where you can talk but you can’t sing, your heart’s working at 70 percent capacity,” he says.

Firnstahl’s exercise plan is backed up by his motivational plan, which is designed to help dieters avoid self-pity and backsliding. And the book is peppered with little everyday tips, such as subscribing to health magazines; each month, the magazines serve as reminders to stick with the plan.

Sure, it may seem like a long haul. But the point, says Firnstahl, is not suffering or obsession but satisfaction.

“Eating right and modest physical activity are both enjoyable,” he affirms.