A new research study at Northwestern University is investigating innovative ways to rehabilitate people with lousy health habits.

Bonnie Spring, a professor of preventive medicine at Northwestern's Feinberg School of Medicine, says the way to improve eating habits is to make change as easy as possible. Her method is based on the Behavioral Economics Theory used by Nobel Prize winner Daniel Kahneman.

The study uses high-tech tools, including a specially programmed Palm Pilot to monitor eating and exercise, virtual visits with a personal coach and an accelerometer which straps around the waist to record the intensity of their movements. Participants are assigned to eat more veggies and fruits or cut down on saturated fat and are encouraged to exercise.

"We're trying to figure out which two behavior changes give you the maximum healthy bang for your buck on all unhealthy behaviors that we're trying to modify," Spring said.

"The new behaviors come along for the ride in one of two ways -- a complementary behavior or a substitute behavior," Spring explained. "If watching TV means you also snack when you watch, then eating and snacking are complementary behaviors for you. If I can get you to cut down on your TV, you'll probably automatically cut down on your snacking. I make your life simpler by just asking you to change one. The complementary behavior is a bonus that comes along for the ride."

"A substitute behavior replaces or crowds out another behavior," Spring said. An example would be eating more fruits and vegetables, so you would nibble strawberries instead of being elbow-deep in a bag of Cheetos.

Spring is anxious to see which two behavior changes best helped people maintain their healthier habits. But she won't know the results until the study ends in 2008.