When it comes to eating habits and body image, you might not think that someone who is too thin would have much in common with someone who is grossly overweight, but that’s the conclusion MSNBC Morning Joe cohost Mika Brzezinski came to when she and her good friend and co-writer Diane Smith embarked on a journey together to confront their obsession with food. Obsessed: America’s Food Addiction—and My Own (Weinstein Books, May) began with a challenge that the two friends gave each other, because they were equally concerned about the other’s health. Brzezinski offered to pay her friend $100,000 to lose 75 pounds and keep it off. Her part of the bargain, which some might find hard to fathom, was similarly difficult: to gain 10 pounds and be satisfied with the way she looked. Both struggled equally to achieve their goals, and now they are much healthier and have improved self-esteem.

“We both had unhealthy bodies and unhealthy minds,” says Brzezinski, who was partaking in an afternoon run while she spoke to Show Daily. “I wasn’t any more healthy than Diane after what I had put my body through for the past 25 years. I don’t know what’s worse, throwing it up, obsessively exercising it off, or allowing yourself to become obese.”

The two decided to write this book to help others have a conversation about self-image and food. After speaking to experts in the fields of medicine, nutrition, and health, they concluded, “You have to take a look at the food environment and the culture we live in that has caused the obesity crisis. Look at the growing amount of science that is calling sugar toxic, that is looking at the amount of salt in our food, that is looking at its addictive qualities.” The book also includes comments from well-known public figures who have been open about their own food problems, including singer Jennifer Hudson, New Jersey’s Gov. Chris Christie, and actress Kathleen Turner.

Asked why both women had a neurotic relationship with food, Brzezinski replies, “It’s very complex, but it has to do with the addictive nature of certain ingredients that are in most of the food we eat, and a certain need for attention—a void in life that food can fill. It becomes a vicious cycle. We both did the same thing to ourselves in different ways. She ruined her metabolism, and mine was shot, too.” She adds, “The experience we went through has given us something to offer the rest of the country. I would love for them to have this much needed conversation.”

Brzezinski signs today at the Perseus Books Group booth (1402) at 10 a.m.