She's a columnist for O, The Oprah Magazine, a sought-after life coach and the author of several best-selling books. Dr. Oz talks with Martha Beck about her latest book, The Four Day Win: End Your Diet War and Achieve Thinner Peace, and about her lifelong struggle with dieting.

Martha says she used evolutionary logic to tackle an issue she struggled with for more than 30 years—dieting. "I started dieting as a teenager, and then I just freaked out and started binging, and that just started a cycle that didn't end for years and kept me away from inner peace," Martha says. "I know a lot of Americans are locked in this and I think it is [caused] by constantly starving ourselves. We are putting our bodies and our very deep, unconscious brains in the position of believing there is a famine."

Martha says data she has studied shows that when your body thinks there is a famine, your brain actually sends you signals to compulsively seek food. To learn how to reverse the dieting and overeating trend, Martha says she interviewed more than 100 people who have lost a significant amount of weight and kept it off. She says part of the secret to their success is setting and following through on a goal of eating healthy for four days straight. "The first three days of a new habit are the hardest," Martha says. "On the fourth day, it's not that you have established a habit, it's that you have just pushed past your initial resistance."

Once you make it past the four-day mark, Martha says your body and brain will soon shift from starvation mode to being on the path to "thinner peace." "What you want to do is fool your unconscious self into believing you live in a time of abundance and plenty where everything is fine," she says. "That means low stress and high levels of personal reward, and it means when you take away something pleasurable, you substitute something pleasurable."

Once you start to eat less, Martha suggests rewarding yourself in ways other than eating, such as shoe shopping or getting a massage. "Whenever you drop your calorie count a little, you have to add something to your life that is deeply nourishing," she says.