When plentiful portions are on offer, we polish them off, according to a recent study.
Barbara Rolls, who led the study, is the author of the Volumetrics weight loss books, in which she explains the concept of calorie density and recommends filling up on soup, fruits and vegetables rather than refined carbs like pasta or extra servings of other foods. Unfortunately, most of us don’t take her sound advice to heart.
Rolls’ recent study showed when participants were served larger portions for an extended period of time they consumed more food in the long run. The study's researchers suggest this may mean the body's biological signals that control the sense of hunger and satiety do not take over and regulate our food intake.
The study is the longest to focus on the effects of increased portion size over time. Rolls presented the findings on October 19, 2005, at an annual meeting of The Obesity Society.
“Living in the age of super size meals and 'huge food,' our study shows that there is a great need for people to be more aware of what and how much food they are served," Rolls said in a news release.
The researchers tracked how much -- and what types of -- food the 23 participants ate during the study, as well as their energy intake over a course of 11 days. The subjects always consumed more food when they were provided with larger portions… unless they were offered vegetables.
"Consistently being presented with bigger portions can have a sneaky effect on energy intake, even for people who don't regularly clean their plates," Rolls stated.
At the end of the study, the participants had consumed about 15 percent more calories per day during the large-portion period. Perhaps even more significantly, the increase was sustained over the entire study period … so they didn’t eat less later on to compensate.
The increased intake translated into an extra 4,500 calories over the duration of the study -- which would result in an average weight gain of approximately 1.25 pounds if no other factors changed (e.g. exercising more to balance out increased caloric intake).
Also of note is the fact that roughly 25 percent of the participants didn’t even notice they were eating larger portions of food.
Rolls suggests employing a few simple dining out portion control strategies such as: ordering an appetizer rather than an entrée; sharing the main course; bringing home a doggie bag; and resigning from the clean plate club.
This article includes information adapted from a news release provided by Pennsylvania State University, [http://live.psu.edu/story/14158].
