Economics drive people to eat more and exercise less, says a new book that provides insight as to why it is difficult to combat obesity.

"There are simply many more incentives to gain weight than to lose it," said Eric Finkelstein, Ph.D., a health economist at Research Triangle Institute (RTI) International and co-author of "The Fattening of America: How the Economy Makes Us Fat, If It Matters, and What to Do About It".

RTI is composed of North Carolina State University in Raleigh, Duke University in Durham, the University of North Carolina at Chapel Hill and North Carolina Central University in Durham.

"We are, in fact, victims of our success as a nation. Unfortunately, the prize is diabetes, stroke and an increased likelihood of disabilities," said Finkelstein.

The book explores the role that business and policy makers play in America's obesity epidemic, and explains that successful obesity strategies need to do exactly the opposite of where the economy is going: the need to make it cheaper and easier to be thin and not fat, RTI says on its website.