This is the premise of his new book, "The Flavor Point Diet" (Rodale Press), based on a phenomenon he said is well studied, but is well known only to appetite researchers--sensory specific satiety.
"We stay hungry longer the more diverse the flavors in a meal or snack," said Katz, a professor in the Department of Epidemiology and Public Health at Yale School of Medicine. "If flavors are thoughtfully distributed, we fill up on fewer calories. This explains why, for instance, people can eat a holiday meal to the point of feeling unpleasantly full, yet still have room for dessert. No, that's not because you have a 'hollow leg!' It's because of sensory specific satiety; the hypothalamus is hard-wired to respond to flavors."
A pilot study of Katz's eating plan was conducted with 20 men and women, and their families, for 12 weeks. Katz said the mean weight loss over that time was 16 pounds with persons losing from 10 to 31 pounds. The study participants also lost body fat and saw their cholesterol, blood sugar, insulin, and blood pressure decline.
He said ethnic foods, such as Italian and Indian, are good examples of flavor thematic eating. Top chefs also plan meals around a harmonious blend of flavors. Katz said sensory specific satiety likely evolved because dietary variety was difficult to achieve when humans had to gather and hunt for food, but was nonetheless vital for survival. It takes a variety of foods to provide all of the nutrients we need. But the survival advantage this trait offered is now a disadvantage because we are exposed constantly to an unprecedented variety of foods. The result is an over-stimulated appetite center, too much eating and weight gain.
Another problem, Katz said, is that the food industry appears to spike processed food with superfluous flavors such as sugar in salty food and salt in sweet food. Often, the consumer cannot even detect these additions because they are accustomed to eating processed foods, and one flavor masks another. For instance, some breakfast cereals have nearly as much salt as potato chips and many types of crackers, sauces, salad dressings and other foods are loaded with sugar. This may not register on your tongue, but it does influence the hypothalamus, where the result is more appetite.
"Flavor additions stimulate the hypothalamus to produce more neuropeptide Y, a hormone that increases appetite, and this is a major reason why people have difficulty exercising portion control," he said. "We say that variety is the spice of life, and in this regard, our diets are just way too spicy." He notes that controlling flavors through subtle repetition and thoughtful distribution so that there is variety over time, without too much variety at any one time, has a soothing influence on the appetite center.
Katz said his motivation for writing the book was the epidemic rise of obesity among children as well as adults, and the fact that obesity is the driving force behind all of the chronic diseases in this country. He also cites the national preoccupation with weight control, and the need to give people an empowering alternative to unbalanced, fad diets.
Katz said his book has three goals: to empower people to pursue their weight loss goals immediately and responsibly; to play a significant role in changing the way America thinks about the very concept of dieting, and to change the food supply.
"There are lots of ways to change the food supply," he said. "You can legislate, litigate or you can change what people demand. If people start buying more and more healthy food, there will be more healthy food available. The food industry, after all, wants to keep the customer satisfied."
The Flavor Point Diet has three phases, each of which makes use of flavor themes, more obvious in the beginning, subtle by the end. The nutritional profile of the diet never changes, and meets or exceeds all prevailing dietary guidelines in every phase. Because of this, Katz notes, a dieter could remain on any phase of the plan indefinitely. In addition, the meal plan is appropriate for all members of a household, from the youngest to the oldest.