"Who would think that the same wine, but just labeled to be from a different part of the country, would not only influence their taste perception of the wine but how much they ate in a dinner situation?" Payne said. "It's hard to believe that a simple environmental change could have that large of an effect. It's unbelievable how gullible we are in terms of advertising and marketing, and how our senses trick us."

In one experiment, people ate more plain oatmeal from a bowl that was infused with a cinnamon and raisin aroma, versus a plain bowl or one infused with the aroma of macaroni and cheese. In another, day-old chocolate cake was rated as better-tasting when it was called Belgian Black Forest Double Chocolate Cake.

The biggest surprise, said Wansink, who was speaking by cell phone while on his way to Canada, is that people don't believe they can be tricked, even when they're shown the evidence.

"They say, 'I'm not fooled by a name on some food, I know what I like."'

Rather than despairing over our gullibility, we can use these same tactics to trick ourselves into eating less and eating better, Wansink says.

You can do simple things, such as using smaller plates or tall and thin glasses, pre-packaging smaller portions of snacks rather than eating right out of a big bag or box, or moving the candy jar off your desk. Give glamorous names to a healthful dishes, such as "Succulent Italian Seafood Fillet."

Wansink found that kids ate more veggies when broccoli was referred to as "Dinosaur Trees," a V-8-type veggie drink was named "Rainforest Smoothie," and peas were labeled "Power Peas."

With these small steps, you can shave off 100-200 calories from your daily intake and drop 10-20 pounds in a year, without feeling deprived.

"The best diet is the one you don't know you're on," he said.

In just about every household, there's a "nutritional gatekeeper" who controls 73 percent of what the family eats, for better or for worse, writes Wansink.

"That was my favorite chapter," he said. "People throw up their hands and say they can't control what their kids eat, but really, you control 73 percent, and you're doing it right now when you have candy or snacks laying around the house, or give them them money to buy french fries and bacon cheeseburgers at school instead of something healthier," he said. "Many parents are doing a terrible job. Each generation learns to cook a little less, and for a while it was out of fashion to be a good cook. That had a terrible impact on nutrition."

It helps to plan meals so you don't resort to the fast food drive-through and make a shopping list so you don't fill your cart with impulse items. When meals are eaten at home, parents can control portions and serve a variety of healthful foods.