April 16, 2013
Learning About Portion Sizes Doesn’t Help Us Stop Overeating
Lee Rannals for redOrbit.com — Your Universe Online
New research from the University of New South Wales (UNSW) indicates our eyes are bigger than our stomachs when it comes to determining appetite.The researchers wrote in the Journal of Health Psychology people given large servings of food eat more than those given smaller servings, despite being knowledgeable about the impact of portion size. They say the study highlights the need to find new ways to reduce the effect of portion size on overeating.
"If no effective approaches are found, it may be necessary to develop policy-related changes to provide a healthier food environment for people," said Dr Lenny Vartanian, a senior lecturer in the UNSW School of Psychology and an author of the paper.
Many studies and documentaries have highlighted how portion sizes in restaurants and at home have increased dramatically since the 1970s, which could be playing a crucial role in the growing obesity epidemic.
"Studies have consistently shown that increases in portion sizes for a wide range of foods and beverages result in increased energy intake. And the impact is not affected by factors such as hunger or the taste of the food," Dr Vartanian said.
Researchers from the current study examined the effectiveness of educating people about portion size and seeing whether it had an effect. Participants in the study were served either a 350 gram portion of macaroni pasta with tomato sauce for lunch, or a 600 gram portion. Those who were educated beforehand were given information about how external factors, like mood, advertising, portion size and social influences can contribute to overeating. Afterwards, they were asked to write about how these factors influenced their food intake.
The team found those in the mindfulness group were taught how to focus on the internal sensations like the taste of food and feelings of hunger and satiety, before they were offered pasta.
"Neither of these brief exercises reduced the effects of portion size. Overall, participants in the larger portion group consumed about a third more pasta — 69 grams — than those in the smaller portion group, " Dr Vartanian said.
One way to try and keep your child from becoming obese would be to try and swap out those larger plates for smaller ones. Researchers reported in the journal Pediatrics last week first-grade students who used smaller plates consumed nearly 50 percent less extra calories than their peers who used adult-sized plates.