Counting Calories? Big Meals Make It Tough

How good are your calorie counting skills? It all depends on the size of the meal.

Studies show that when people eat small meals, they are surprisingly accurate at guessing the calorie content. But when diners try to guess the calorie content of a large meal, most people get it wrong.

In the past, several studies have shown that thin people do a better job estimating the calories on their plate than people who are overweight. Some experts believe overweight people underestimate the calories they eat because they are embarrassed or in denial about their eating habits. But Cornell University researcher Brian Wansink theorized that it’s not the size of the person that matters when it comes to estimating calories. He believed it was the size of the meal that throws us off when trying to guess how much we are really eating. Because overweight people tend to eat more, their errors in calorie estimation are larger as well.

To check his theory, he asked 105 diners to guess the calorie content of a meal they ordered and ate. Then they were shown pictures of 15 different meals, ranging from 445 calories to 1780 calories.

The diners almost perfectly guessed the calories in the small meals. But as portions got bigger, calorie estimates were off by as much as 30 percent, according to the report published in the Annals of Internal Medicine last year. Importantly, whether the person was of normal weight or overweight didn’t affect accuracy.

The data are important because doctors and family members often believe people who are overweight are “lying to themselves'’ when they say they are eating reasonable amounts. “Doctors need to realize that overweight patients are no less accurate in their ability to guess calories than normal weight people,'’ writes Dr. Wansink in the Annals study. “Regardless of weight, everyone has the same intrinsic perception of calorie content.’’

Dr. Wansink says it’s important for people to know that even nutrition experts aren’t good at guessing the calorie content of large portions. His suggestion? When you sit down to a large meal, assume that the calorie content is about twice what you think it is.

Taken From: New York Times Blog