With a parade of home-cooked family dinners and sugary goodies all around, the holidays can mean disaster for your diet. But one expert says avoiding temptation can be easy. Our Tamara Lindstrom got tips from the food guru who's changing the way we think about food.

  To view our videos, you need to
enable JavaScript. Learn how.
install Adobe Flash 9 or above. Install now.

Then come back here and refresh the page.

"You're surrounded by the things that are most likely to cause you to overeat," said Dr. Brian Wansink, director of the Food and Brand Lab at Cornell University. "You're surrounded by tremendously convenient food, you're surrounded by tremendously tasty food and you're surrounded by people that distract you."

Those are distractions that can be disastrous to your diet. Wansink has been studying the way we eat for nearly 20 years. He has been featured on Oprah and CNN and what he has found may surprise you.

"People believe that they know when they're full. No they don't. Our stomach can't count, so we end up deciding how much we eat based on our eyes," Wansink said.

To prove this theory, Wansink conducted a clever experiment with the help of a bottomless soup bowl.

"What we found is that if someone is eating from a six quart refillable bowl of soup that they didn't know was refilling, they would end up eating about 73 percent more soup than the guy sitting right next to him. When we asked him, 'hey are you full?' They would say, 'no, how could I be full? I still have half a bowl of soup left,'" Wamsink said.

But it doesn't take a trick bowl. Your holiday plate could be fooling you into eating more as well.

"What we've also found here at the Cornell Food and Brand Lab is simply the size of a plate is the biggest determinant of how much you serve yourself," Wansink said.

But the doctor offers solutions to help keep tabs on how much you eat, like saving your appetite for foods that are homemade.

"Don't end up filling up on the crackers and the candies and the peanuts. Hold off until you can get the real stuff. That way you're not going to offend that hostess and you're also not going to end up overeating," he said.

As for the cook, Wansink says talking up your food can actually make it taste better to your guests. He suggests spending less time working on your recipe and more time working on a good name for it.

To see tips and learn more about Wansink's research, visit www.mindlesseating.org.