Memory of a previous meal can affect appetite
Posted: Dec 6, 2012 11:26 AM ET
Last Updated: Dec 6, 2012 12:26 PM ET
Remembering a large meal may make people feel fuller but an inaccurate memory can have opposite effect, a small experiment suggests.
Researchers showed 100 volunteers either a small or large portion of tomato soup before lunch and then used a hidden pump to refill or empty the bowl without the diner noticing.Remembering a large meal may make people feel fuller but an inaccurate memory can have opposite effect, a small experiment suggests. (Mark Ralston/AFP/Getty)
"For the first time, this manipulation exposed the independent and important contribution of memory processes to satiety," Jeffrey Brunstrom of the University of Bristol's nutrition and behaviour unit and his co-authors concluded in the December issue of the journal PLoS One, published by the Public Library of Science.
"Opportunities exist to capitalize on this finding to reduce energy intake in humans."
Immediately after the meal, self-reported hunger was influenced by the amount of soup consumed, the researchers said.
But two and three hours after the meal ended, the pattern switched and hunger was predicted by the perceived amount in the bowl at the beginning of the meal rather than the actual amount.
Those who were shown 500 ml of soup experienced greater satiety or fullness than those shown 300 ml.
On the second day, researchers looked at expected satiation for the two groups. They all received 400 ml of soup.
Participants were also asked an open-ended question about the purpose of the study. The six who answered that the soup was artificially refilled or drained were excluded.
No need to cue memory of meal
Previous research by another team showed that reminding people of a recent meal can reduce how much is eaten at a later meal, an effect that lasts for hours but only when the memory of a very recent meal is recalled.
Brunstrom's team said the new findings suggest that the role of memory is substantial and can be triggered without explicitly cueing a memory of a recent meal. In the latest experiment, participants were never told to try to remember how much they ate.
Scientists have also observed that eating while distracted, which could interrupt memory, also seems to hinder how we respond to signals of feeling full.
But Brunstrom's team couldn't draw a cause-and-effect relationship between hunger and memory.
Other factors could be involved, such as if someone who saw a 300 ml portion was disappointed by the small size and responded negatively by rating their hunger higher than those who saw 500 ml of soup.
The researchers suggested measuring mood and satisfaction with portions in future experiments to take that possibility into consideration.
The study was funded by the UK's Biotechnology and Biological Sciences Research Council.
Top News Headlines
- 30,000 Canadians are homeless every night
- A new national report into homelessness in this country tells a grim story — at least 200,000 Canadians experience homelessness in any given year and least 30,000 Canadians are homeless on any given night. more »
- Obesity called a disease by U.S. doctors group
- In order to fight what it described as an "obesity epidemic," the American Medical Association voted to recognize obesity as a disease and recommended a number of measures to fight it. more »
- Neil Macdonald: Washington's obsession with leakers
- Julian Assange and Edward Snowden are just the most prominent targets in an all-out legal and propaganda campaign that America's security apparatus is mounting against leakers everywhere, Neil Macdonald writes. more »
- How open is Ottawa's new 'open data' website?
- Treasury Board President Tony Clement is touting the federal government's revamped data portal as a "new natural resource." But that online window for previously published data arrives at the same time the government faces controversy over just how open it really is. more »
Latest Technology & Science News Headlines
- How open is Ottawa's new 'open data' website?
- 'Tweet' gets new entries in Oxford dictionary
- Tweeting in the social-networking sense has become so pervasive that the Oxford English Dictionary has broken one of its own rules to add new meanings for "tweet" as both a noun and a verb. more »
- High levels of radiation found in groundwater at Fukushima
- High levels of a toxic substance called strontium-90 are found in groundwater at the devastated Fukushima Daiichi power plant in Japan — coming to light even as the country moves closer to bringing its nuclear reactors back online. more »
- Crowdfunding websites trying to cash in on crowded field
- Success stories make it seem like crowdfunding websites drop cash from the heavens on to any deserving idea. But regulators and big banks are now taking a closer look at the controversial new field, Dianne Buckner writes. more »
- Twitter taught in Grade 1 class in Windsor, Ont.
- A teacher in Windsor, Ont., is teaching her first and second grade students to tweet, blog and Skype as part of the elementary curriculum. more »
Bob McDonald's Blog
- After Hadfield, who's the next Canadian in space? Jun. 13, 2013 12:01 PM Canada's singing astronaut announced his retirement this week, leaving Jeremy Hansen and David Saint-Jacques to fill his space boots. But there is no date set for when the next Canadian will fly in space.
Quirks & Quarks
- June 22: How to Build a Brain Jun. 19, 2013 10:42 AM Scientists are embarking on ambitious projects to understand the incredible complexity of the human brain and to simulate it in a computer. They hope it will help us understand mental disorders, as well as the nature of thought, memory, and conciousness.
- 2 men jailed in Dominican wedding fight back in Canada
- Bob Rae stepping down as an MP
- Half of First Nations children live in poverty
- All-party deal on bills, MP oversight lets House out early
- Are e-cigarettes safe to puff?
- Huge ancient city at Angkor Wat revealed by lasers
- Tim Hortons being circled by Wall Street hedge funds
- B.C. teacher duct-taped students' mouths
- Most groups don't want return of Trudeau speaking fees