Impact of portion size on overeating is hard to overcome

People given large servings of food eat more than those given smaller servings, even after they have been taught about the impact of portion size on consumption, research from the University of New South Wales shows.

Learning how to engage in mindful - rather than mindless – eating also did not decrease by a significant amount in those given large servings.

The study, published in the Journal of Health Psychology, highlights the need to find new ways to reduce the effect of on overeating.

"If no effective approaches are found, it may be necessary to develop policy-related changes to provide a healthier for people," said Dr

Lenny Vartanian, a senior lecturer in the UNSW School of Psychology and an author of the paper.

Portion sizes in restaurant and at home have increased dramatically since the early 1970s, and are thought to have contributed to rising obesity levels.

"Studies have consistently shown that increases in portion sizes for a wide range of foods and beverages result in increased . And the impact is not affected by factors such as hunger or the taste of the ," Dr Vartanian said.

The team's study of 96 women is the first to examine the effectiveness of educating people about this phenomenon. Participants were served either a 350 gram portion of macaroni pasta with tomato sauce for lunch, or a 600 gram portion.

Those in the education group were given a brochure about how external factors, such as mood, advertising, portion size, and social and cultural influences can contribute to overeating, and then asked to write about how these factors had influenced their food intake in the past.

Those in the mindfulness group were also taught how to focus on the internal sensations such as the taste of food and feelings of hunger and satiety, before they were offered the 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.

This difference amounts to about 87 kilocalories, or 365 kilojoules, of extra energy.

add to favorites email to friend print save as pdf

Related Stories

Low Literacy Can Lead to Food 'Portion Distortion'

Feb 26, 2009

(PhysOrg.com) -- How big is a serving of spaghetti or a cup of cranberry juice? Correctly estimating the size of a food serving is important for maintaining a healthy weight, but a new study suggests people with lower literacy ...

Could our minds be tricked into satisfying our stomachs?

Jul 13, 2010

Research to be presented at the Annual Meeting of the Society for the Study of Ingestive Behavior (SSIB), the foremost society for research into all aspects of eating and drinking behavior, suggests that the key to losing ...

Recommended for you

Background TV can be bad for kids

1 hour ago

Parents, turn off the television when your children are with you. And when you do let them watch, make sure the programs stimulate their interest in learning.

Many kids with medicaid use ER as doctor's office: CDC

1 hour ago

(HealthDay)—Children covered by Medicaid, the publicly funded insurance program for the poor, visit the emergency room for medical care far more often than uninsured or privately insured youngsters, a U.S. ...

Warning: Birthdays can be bad for your health

2 hours ago

New research has found that birthday-related drinking is associated with upsurges in hospital admissions among young people. This study of drinking behaviour in Ontario, Canada is published online today in the scientific ...

User comments