Ever grabbed a handful of chips and then polished off the whole bag before you even realized it? Why is it so hard to stop overeating, even when we know we should?
That's a question Dr. David Kessler set out to answer in his new book, "The End of Overeating."
As the former commissioner of the U.S. Food and Drug Administration under the Clinton and Bush administrations, the growing obesity epidemic was a subject he was well versed in. It was also one with which he had personal experience.
"I have suits in every size. I have gained and lost weight several times during my lifetime," Kessler told Canada AM Monday.
Kessler said he was motivated to write the book after watching a woman on "Oprah" who said she ate all the time: when she was happy, when she was sad, when she was hungry and when she wasn't.
"I wanted to understand what was driving this woman to do what she didn't even want to do. That was the question," explained Kessler.
So he looked into what had been researched on food and brain reactions. He found neuroscientists are increasingly reporting that fat-and-sugar combinations, in particular, light up the brain's pleasure centre -- the dopamine pathway -- the same brain area that lights up in people addicted to alcohol or drugs.
There are three combinations in particular that become like a drug to some people, Kessler believes: fat-sugar, fat-salt and fat-sugar-salt.
Food companies know all too well how addictive these substances are, and load their products with them. These foods then become available everywhere, 24 hours a day, Kessler says.
"Layered and loaded" foods, as he calls them, can be irresistible. They create a willpower-sapping drive to eat more of them, even when we're not hungry. By giving in to the desire, we build a craving. And the more we crave a food, the more the food's reward value is increased, making it even harder to resist.
When you consume the layered and loaded foods, your brain compels you to seek it out again - often without you even realizing your brain has learned this.
"It's not your fault. Your brain is being hijacked," insists Kessler.
"For the first time we can say to people we understand what's going on. If you take these fat-sugar and fat-salt foods and put them on every street corner, it's not a matter of willpower; your brain has been activated."
Some people can resist this food conditioning because of other factors, such as their metabolism and hormones, both of which are partly affected by activity levels and genes.
Judging by the growing obesity crisis in North America, more of us are giving in our food cravings more often. But Kessler believes there is still hope that Canadians can halt the epidemic.
"In the States, one out of three Americans is obese. In Canada, you're at one of four. You still have cultural norms in your favour. You don't eat out as much as we do in the States. You don't eat between meals as much as we do in the States. But the real question is: where is Canada going to be over the next decade?"
Kessler says food companies and governments need to take some responsibility by providing consumers with greater disclosure of what's in our food. But consumers need to understand what's driving their behaviour as well, and then putting steps into place to change it.
"It's about cooling down the stimulus. It's how you look at a plate of chocolate chip cookies. It's asking yourself: is that going to satisfy me or is that just going to stimulate me?"
