Still, that may be just what happens. "The ability to eat calories to simply sustain health has all but been lost," says Kim Gorman, weight management program director at the Center for Human Nutrition at the University of Colorado in Denver.
Study after study has shown that the more people have on their plates -- or in their bags of chips or boxes of popcorn -- the more they're likely to eat. Even the size of a plate (or bowl or spoon) can influence how much people eat. For example, in a study reported by Brian Wansink, then a food psychology professor at Cornell University, in his 2006 book "Mindless Eating," people served themselves more on a bigger plate than on a smaller one. In another study led by Wansink and published in the American Journal of Preventive Medicine in the same year, 85 nutrition experts served themselves more ice cream when given a larger bowl and spoon than when given a smaller bowl and spoon -- and most of them proceeded to eat the full portion.
Not all research in this area points in the same direction, however. Rolls, for example, led a team that found plate size did not influence how much people actually ate whether food was served to them or they served themselves.
The study, published in the journal Appetite in 2007, also found that when people served themselves from a buffet, the ones who were given the smallest plate went back for refills more often than those with bigger plates.
--
'Something easier'
In general, portion-control plates try to make portions equal to serving sizes recommended by the government's Food Pyramid and ones used in product labeling. "We take these nutritional guidelines and translate them right onto the plate," says Carol Jubert, program designer for Portion Doctor made by Portion Health Products in St. Augustine, Fla.
For example, the Portion Doctor plate is divided into three sections -- the largest meant to hold a cup of vegetables, another to hold half a cup of potatoes, pasta or rice, and the third to hold 3 ounces of meat, poultry or fish.
Another product, the EZ Weight plate, distributed by L&L of Luling in Luling, La., is divided into eight compartments: two teaspoon-size, two tablespoon-size, two that hold a cup each, one that holds two-thirds cup and one that holds 6 ounces. It comes with an instruction manual that lists recommended amounts of various foods.
