A major cause of overeating is eating too many flavors all at once, triggering the hypothalamus in the brain to ask for more food, says David Katz, M.D.
Dr Katz of the Prevention Research Center and the Rudd Food Center for Food Policy & Obesity at Yale University, has written a new book, "The Flavor Point Diet", based on a phenomenon he said is well studied, but is well known only to appetite researchers—sensory specific satiety.
"The longer we stay hungry, 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. It's because of sensory specific satiety; the hypothalamus strongly responds to flavors."
In a pilot study of Katz's eating plan conducted for 12 weeks on 20 men and women and their families, the mean weight loss 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 most likely evolved because dietary variety was difficult to achieve when humans had to gather and hunt for food. It takes a variety of foods to provide all of nutrients we need. But the survival advantage this trait offered our ancestors is now a disadvantage because we are perpetually exposed to an unprecedented variety of foods. The result is an over-stimulated appetite center, too much eating and weight gain.
Another problem, according to Katz, is that the food industry appears to spike processed food with superfluous flavors such as sugar in salty food and salt in sweet food, which is often not detectable as 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 the tongue, but it does influence the hypothalamus, and 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. 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.
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.