Put that platter in front of us, and it's history. Americans learned too well the lessons at mother's dinner table: Eat what's on your plate -- all of it! Unfortunately, that attitude has helped create a nation of fat people.
Most people don't know what an "appropriate portion" is, points out researcher Barbara J. Rolls, PhD, professor of nutrition at Pennsylvania State University. She has published a paper about food portions and consumption in the December American Journal of Clinical Nutrition.
In fact, Rolls says, they don't even notice if they're given more food than they should eat.
The Penn State researchers designed their study around a truly all-American dish -- macaroni and cheese -- to see just how far a random group of adults would push the fork.
On four separate days, 51 men and women -- described as normal and overweight -- come to the laboratory to eat their mac 'n cheese lunch. One group received one of four portion sizes on a plate, from 500 to 1,000 grams. The second group received a plate and was allowed to serve themselves as much as they wanted.
Each person sat in a private cubicle to eat their meal, and each was told to eat as much or as little as they wanted.
Afterward came the questions: How much food did you think you ate? Are you full or not? Are you thirsty? Are you nauseated?
The researchers found that portion size influenced the amount of food they ate. The subjects consumed more calories when larger portions where served, whether they served themselves or they ate a predetermined portion.
People in both groups ate "significantly greater amounts of the lunch entree as portion size increased," writes Rolls. They consumed 30% more when they were offered the largest portion than when they were offered the smallest portion.
Many people were big-time plate cleaners. Eight men and two women ate everything on their plates at some meals. The researchers conclude that men and women, normal weight and overweight, restrained and unrestrained eaters -- all showed the same response to portion size.
In fact, the more they ate, the more satisfied they felt. No sign of nausea in this group. Researchers say people need to be educated on what an adequate portion size really is.
SOURCE: American Journal of Clinical Nutrition
