It's no secret that America is facing an epidemic of obesity. David Kessler, former head of the U.S. Food and Drug Administration, spent the past seven years trying to discover what drives Americans to overeat. He came to a conclusion that it's not a lack of willpower, and it's not even their fault. As he explains in his new book, The End of Overeating, they've become addicted to food.

Kessler wanted to understand: Why are Americans today heavier than ever? Why can't people resist certain foods? Why do they keep eating long after they are full?

"We no longer just eat at meals," he says. "We've made it available 24/7. We eat anytime. We've made it socially acceptable to walk down the street and eat, to eat in business meetings. We've, in essence, made food into entertainment."

Food makers feed desire for unhealthy snacks

Kessler talked with top scientists, physicians and food industry insiders. He says corporate food processors and restaurant chains use ingredients that feed our desire to want more.

"We've taken fat, sugar and salt and put it on every corner," he says.

Fat, sugar and salt alter the brain's chemistry and drive what he calls conditioned hyper-eating.

"It's not just the fat and sugar and salt, but it's the anticipation - the food cues - that are activating our brains, that are activating the wanting," he says. "So what's happening is we're getting constantly bombarded with these food cues. Our brains are constantly being activated. We're being aroused. Our attention is grabbed, and we keep on coming back for more and more."

Kessler sees parallels between the tobacco and food industries. Both, he says, manipulate consumer behavior to sell products, regardless of the impact on consumers' health. So instead of just satisfying hunger, the food industry is designing foods to induce people to eat more than they should. More, even, than they would otherwise want.

"They certainly understand the inputs. They know the outputs: that people come back for more," he says. "They certainly have loaded the food and layered it, [with] layer upon layer of fat, sugar and salt."

Tactics derail attempts to lose weight

Those foods stimulate the brain to release dopamine, which makes us feel good. Soon, just the thought of those foods prompts a craving for them. That constant stimulation, Kessler says, dooms most attempts to lose weight.

"Diets are not going to work once your brain's circuitry [is] wired and your behavior had become conditioned and driven to respond to fat, sugar and salt," he says. "Certainly, I can deprive you of food for 30 days or 60 days, and put you on a diet. You can get through that, and you'll lose weight. But then I put you back in your environment and you have that same old circuitry in your brain - of course, you're going to gain back the weight."

Taming cravings

In his new book, The End of Overeating, Kessler suggests a strategy to end what he calls the food addiction - starting with understanding why people crave certain foods.

"The first thing you have to do is cool the stimulus," he says. "The more you want the food? Do you ever have this inner dialogue: 'Boy, that would taste great!' 'No, I shouldn't have it.' 'Yes, I want that.' 'No, I shouldn't.' That only increases the reward value of food. You have to protect yourself from your brain being activated."

And the best way to do that, he says, is to change how we look at food.

"You'd need to develop rules for yourself. Some people become vegetarians," he says. "That makes it easy, because then they look at animal fats and protein and say, 'No, I don't want that.' Some people look at food and say, 'I don't want processed foods; I only want real foods.' I look at these big portions and I say, 'Boy, I don't want all that food. That's two, three, four times what I need. I'd rather have smaller amounts.'

"We have to re-learn how to eat. You have to decide what's going to work for you. There are certain foods I know I just can't eat. If I start eating french fries, I'm just going to eat the whole thing. So it's easier in fact to develop a rule and say, 'I'm not going to eat it.' It decreases the brain activation."

When Kessler was commissioner of the U.S. Food and Drug Administration, the FDA enacted regulations requiring standardized nutrition labels on food sold in stores. Now, he'd like to see that mandate expanded to include items on restaurant menus. Information, education and a change in perception, he says, are the keys to taking control of our diet and ending the nation's epidemic of overeating.