Ithaca, N.Y. ? A university professor argues that a good way to lose weight is not by obsessing about carbs or banning trans fats, but by addressing dietary “hidden persuaders.”

Cornell University marketing professor Brian Wansink’s goal is to uncover hidden cues that influence how much people eat. He wants to know if people grab more candy from a bowl if there are more colors (yes), and whether the subtle prompts like mood and setting that affect their eating (generally, no).

He lays out the case in his new book, “Mindless Eating, Why We Eat More than We Think We Eat.”

“So much of the answer lies not in counting calories, not in legislating, but in the middle range of what we can do by changing some of our own habits,” Wansink said in his Food and Brand Lab on Cornell’s upstate New York campus.

The lab’s main room is designed to look like a kitchen, although this kitchen has tiny surveillance cameras, a two-way mirror and a food scale hidden beneath a dishrag on the counter. The idea is to provide a homey atmosphere where test subjects can eat, and an unobtrusive way for researchers to watch.

Supper subterfuge

On a recent day, Wansink leaned close into the two-way mirror as postdoctoral researcher Collin Payne served Beefaroni and vegetables to a test subject – only to cough on the dish before he got to her seat.

Cornell University professor Brian Wansink, 46, author of Mindless

The cough was choreographed, a ruse to force her to dish herself another serving, this time on a slightly smaller plate. Wansink wants to know if she will dole out a smaller portion on the smaller plate, which she does.

This sort of clever subterfuge is common to Wansink’s experiments. Wansink once designed self-filling bowls that pump tomato soup up from under the table as people supped from them. He wanted to find out if people stopped eating without the visual cue of an empty bowl. Some people ate more than a quart.

Another time, when he was at the University of Illinois at Urbana-Champaign, he told half the diners at a restaurant/lab that their complementary glass of Cabernet Sauvignon that night came from California. The other half were told the same wine came from North Dakota. Not only did the North Dakota group eat less of their dinner, they headed for the exits quicker.

Same wine, same food, different cues, different results.

Wansink’s larger point is that people make more than 200 food decisions a day, most of them subconsciously. He believes people trying fad diets would be better served changing little behaviors that could cut a relatively painless 100-200 calories a day. It can be done in part by hiding the candy or avoiding jumbo-size packaging, which tends to encourage consumption.

Pick two or three habits a month, he advises. For instance, Wansink this month is trying not to eat a snack unless he first eats fruit, and he set a one-roll limit for meals out.

Brains help explain

Wansink’s “ingenious” study designs set him apart in the nascent field of investigating what motivates people to eat, said Andrew Geier, a Ph.D. candidate at the University of Pennsylvania who has published eating behavior research.

“He’s leading the way in trying to explain eating behavior from the nose up,” said Geier.

Wansink’s Ph.D. is in marketing and consumer behavior, unusual in a field full of researchers with psychology backgrounds.

Some of his most provocative work casts doubt on the value of nutrition labels for consumers. He believes people are either too busy or distracted to read packages. Worse, labels can lull people into a false sense of security, like Subway diners feeling good about eating a low-fat sandwich, and then loading up on chips and a soda.

Eating a sandwich for lunch on campus, he notices a label on his mayonnaise packet: “As always 0g carbs.”

“I love it!” he said with a laugh.

The packet doesn’t mention that a single serving has 10 grams of fat and 90 calories.