Obesity doctor says limiting flavors is the key to a successful diet

CHICAGO -- Forget counting carbs and calories. Obesity researcher Dr. David Katz says the way to lose weight is to limit flavors.

Katz, director of Yale University's Prevention Research Center, says people stop eating when the brain's appetite center registers "full." But eating lots of flavors promotes overeating because different sensors must register full for appetite to subside, Katz says.

The typical American diet "is a mad cacophony of flavors," Katz said this week during a book-tour stop in Chicago.

Instead, Katz advocates flavor-themed meals -- an apple day, for example, or a sesame day, even an occasional chocolate day.

The idea is perhaps less boring than it sounds. For example, pineapple day features pineapple juice and cereal for breakfast; pineapple-walnut chicken salad and crackers for lunch; pineapple shrimp, bulgur, sauteed peas and tossed salad for dinner; and caramelized pineapple rings for dessert.

The theory and practice are detailed in Katz's new book, "The Flavor Point Diet," based on a little-publicized phenomenon called sensory-specific satiety. That is the term used to describe the way food becomes less palatable when enough of it is eaten. Adding a new flavor renews the process, numerous studies have shown.

Katz, 42, the trim, youthful medical contributor to ABC News and a nutrition columnist for Oprah Winfrey's magazine, tested the diet on 20 people for 12 weeks and said they lost an average of more than 16 pounds.

Jonathan Link, a 34-year-old information services specialist from New Milford, Conn., was one of them. Link -- who was 5 feet 9 inches and 183 pounds, with high cholesterol -- was skeptical at first.

"I thought, 'Oh, that's disgusting, you have to eat peaches all day,"' Link said.

But Link said the diet was surprisingly varied. He lost about 20 pounds early last year and has kept it off by permanently changing his eating habits.

"By week two, I started getting stuffed. I couldn't even finish dinner because I was feeling so full," Link said.

Katz recommends 30 minutes of moderate exercise most days. His flavor theme builds on the diets many nutritionists advocate -- lots of fruits and vegetables, whole grains and nuts; fish and poultry for protein; limited fat; and healthy snacks.

Brown University researcher Hollie Raynor, who has studied sensory-specific satiety, said many diets are based on a more extreme interpretation of the concept, including ice cream diets, soup diets and diets that severely restrict carbohydrates.

Whether Katz's diet works because it limits flavors, or because it promotes healthy eating and exercise, is unclear, Raynor said. "If you're eating healthy and exercising, you're going to lose weight," she said.

Susan Burke, chief nutritionist for ediets.com, a weight-management Web site, said there is some validity to Katz's flavor theory. "Jumbling flavors at any one meal can trigger you to eat more," Burke said.

"Whether or not the science will bear out that this actually is the cause of the weight loss" is unclear, Burke said. But she added: "At the very least, this program you can be assured is going to be nutritious."