How many times have you sat in front of your television, shoveling handfuls of chips into your mouth. By the time you stop to think about what you're doing, the entire bag is empty and, in retrospect, you weren't even that hungry to begin with.

Dr. Brian Wansink, Professor of Marketing at Cornell University and founder of the Food and Brand Lab, started a campaign to investigate this phenomenon. Over the course of hundreds of studies, he found that everything from lighting to the shape of a glass affected how much we consumed, and published his results in his bestselling book Mindless Eating: Why We Eat More Than We Think. His studies have effectively changed the way brands market food to consumers.

We spoke with Dr. Wansink about what triggered his interest in stopping mindless eating and asked him for some fundamental tips to prevent yourself from consuming excess calories without even knowing it.

Origins of the Mindless Eating Campaign

According to Wansink, his interest in food started at an early age. "I used to sell vegetables door-to-door and it was always amazing to me that, regardless of how smart a person appeared to be, whether they bought vegetables or didn't buy vegetables off my little wagon, if you asked them why, they really couldn't give you an explanation," he says. "Here we have something as amazing—as important—as food, and most people have very little idea why they eat what they eat or why they prefer what they prefer."

In 1997, he founded the Food and Brand Lab at the University of Illinois to experiment with what affected a person's decision-making process when it came to food. Some of their experiments included a bottomless soup bowl that automatically refilled allowing participants to eat as much as they wanted until they were full and testing how the shape of a glass affected how much alcohol a bartender poured.

Surprising Findings

While it isn't particularly shocking that environmental factors affect food decisions, it was shocking just how much, and just how small the details. "These little cues around us enormously rule us in one direction or the other in terms of making us eat too much or making us eat the wrong thing. Whether it be the lighting or the size of the plate or what the person next to us is doing—they have tremendous influences because we aren't that aware of what's going on," Wansink explains.

But the finding that was most surprising was how much people were in denial. "I've done 300 or 400 of these studies, and what's most amazing to me is that, of all the people involved in this—there have been probably tens of thousands of people—they claim they were uninfluenced by the cue around them," he says. "This stuff is so powerful because we don't want to believe we're influenced by it."

The Factors

Plate Size: "One thing we've found is simply that if you go from a 10-inch to a 12-inch plate, you'll serve about 22 percent more food," Wansink explains. "The pasta you dish out onto a 10-inch plate makes the full plate, but you can fit 10 ounces onto a 12-inch plate and it doesn't even look like an appetizer, so you plop down another ounce." Therefore, "if you ask people who have eaten four ounces on a 10-inch plate or five ounces on a 12-inch plate, most of them claim to be really full because in both their minds, they've eaten a full plate of food."

Watching Other People: "If you're a woman following a woman in a buffet line, 44 percent of what you will eat will have been determined by what the person ahead of you eats. If they eat a lot, you eat a lot; if they eat a little, you eat a little," Wansink says.

Accessibility: "It's also the distance of foods. In one of our studies, we found that leaving a candy dish just six feet from a person's desk decreased how much they ate by four to nine chocolates a day. When we ask them if the extra six feet is that much work, they say no, but it gives them a moment to pause and ask themselves, 'How much do I really want that chocolate?' Not very much."

Labels: Wansink's studies also found that people ate approximately 16 to 23 percent more calories when the food was labeled "low-fat."

How to Stop Mindless Eating

"It's the cues around you, the availability of food, or visibility of food," Wansink says. "Don't have big dishes around, move your snacks so they're six to four feet out of the way, make sure the first thing you see when you open a cupboard or a refrigerator isn't the least healthy thing in there," he advises. Don't buy unhealthy snack foods in bulk.

Eating at the table as opposed to on your sofa or in front of the television have also played factors in mindless eating. When you have something like a television distracting you from listening to your body's cues that you're full, you tend to continue eating.

Forcing yourself not to be influenced by what people around you are loading onto their plates is a struggle, but acknowledging that watching a friend order a slice of cake makes you feel like it's OK, is the first step in the battle.

Ultimately, it's about "what you eat, how much you eat and how frequently you eat," Wansink says. But as Mindless Eating: Why We Eat More Than We Think says, "The best diet is the one you don't know you're on."