Skip to content
Health, Sports & Psychology

Why the size of your plate might be making you overweight

Updated Tuesday 15th September 2015

Alan Partridge's trick of taking an extra-large plate to an all-you-can-eat buffet might be putting his long term health at risk. New research links tableware size with the tendency to eat too much.

A new review has produced the most conclusive evidence to date that people consume more food or non-alcoholic drinks when offered larger sized portions or when they use larger items of tableware.

The research, carried out by the University of Cambridge and published in the Cochrane Database of Systematic Reviews, suggests that eliminating larger-sized portions from the diet completely could reduce energy intake by up to 16% among UK adults or 29% among US adults.

Woman drinking from a double-sized cup Creative commons image Icon Russell Bernice under a CC-BY licence under Creative-Commons license The Double-Sized Big Gulp cup was a marketing gimmick - but could large-sized cups, plates and packages be encouraging us to over-eat?

Overeating increases the risks of heart disease, diabetes, and many cancers, which are among the leading causes of ill health and premature death. However, the extent to which this overconsumption might be attributed to ‘overserving’ of larger-sized portions of food and drink has not been known.

As part of their systematic review of the evidence, researchers at the Behaviour and Health Research Unit combined results from 61 high quality studies, capturing data from 6,711 participants, to investigate the influence of portion, package and tableware size on food consumption. These results are published in the Cochrane Database of Systematic Reviews.

The data showed that people consistently consume more food and drink when offered larger-sized portions, packages or tableware than when offered smaller-sized versions, suggesting that, if sustained reductions in exposure to large sizes could be achieved across the whole diet, this could reduce average daily energy consumed from food by 12% to 16% among adults in the UK (equivalent of up to 279 kcals per day) or by 22% to 29% among US adults (equivalent of up to 527 kcals per day). The researchers did not find that the size of this effect varied substantively between men and women, or by people’s body mass index, susceptibility to hunger, or tendency to consciously control their eating behaviour.

Dr Gareth Hollands from the Behaviour and Health Research Unit, who co-led the review, says: “It may seem obvious that the larger the portion size, the more people eat, but until this systematic review the evidence for this effect has been fragmented, so the overall picture has, until now, been unclear. There has also been a tendency to portray personal characteristics like being overweight or a lack of self-control as the main reason people overeat.

“In fact, the situation is far more complex. Our findings highlight the important role of environmental influences on food consumption. Helping people to avoid ‘overserving’ themselves or others with larger portions of food or drink by reducing their size, availability and appeal in shops, restaurants and in the home, is likely to be a good way of helping lots of people to reduce their risk of overeating.”

However, the researchers point out that large reductions are likely to be needed to achieve the changes in food consumption suggested by their results. Also, the review does not establish conclusively whether reducing portions at the smaller end of the size range can be as effective in reducing food consumption as reductions at the larger end of the range. Critically, there is also a current lack of evidence to establish whether meaningful short-term changes in the quantities of food people consume are likely to translate into sustained or meaningful reductions in consumption over the longer-term.

The researchers highlight a range of potential actions that could be taken to reduce the size, availability or appeal of larger-sized portions, packages and tableware, including: upper-limits on serving sizes of energy-dense foods and drinks (for example, fatty foods, desserts and sugary drinks), or on the sizes of crockery, cutlery and glasses provided for use in their consumption; placing larger portion sizes further away from purchasers to make them less accessible; and demarcating single portion sizes in packaging through wrapping or a visual cue.

However, as Dr Hollands says: “With the notable exception of directly controlling the sizes of the foods people consume, reliable evidence as to the effectiveness of specific actions to reduce the size, availability or appeal of larger-sized food portions is currently lacking and urgently needed.”

Other potential actions include: restricting pricing practices whereby larger portion and package sizes cost less in relative (and sometimes absolute) monetary terms than smaller sizes and thus offer greater value for money to consumers; and restricting price promotions on larger portion and package sizes. The researchers suggest that some of the highlighted actions to limit portion size are likely to require regulation or legislation, helped by active demand from the public for changes to the food environment.

“At the moment, it is all too easy – and often better value for money – for us to eat or drink too much,” said Ian Shemilt, who co-led the review. “The evidence is compelling now that actions that reduce the size, availability and appeal of large servings can make a difference to the amounts people eat and drink, and we hope that our findings will provide fresh impetus for discussions on how this can be achieved in a range of public sector and commercial settings.”

Try our free course The Science of Nutrition

Read more about the research at the Cambridge University website

 

For further information, take a look at our frequently asked questions which may give you the support you need.

Have a question?

Other content you may like

Is it true that the poorer you are, the more likely you are to eat junk food? Copyright free image Icon Copyright free: GinniDeVille article icon

Health, Sports & Psychology 

Is it true that the poorer you are, the more likely you are to eat junk food?

New American research suggests that - perhaps aptly - there's an bulge in the middle of income strata when it comes to tucking into fast food.

Article
Is it possible to have respect for the poor and homeless? Copyright free image Icon Copyright free: Johny Rebel article icon

Society, Politics & Law 

Is it possible to have respect for the poor and homeless?

During a campaign interview, Theresa May speculated on why people might visit foodbanks. The OU's Dr Dave Middleton asks if there's a balance between respectfully giving, and giving respect.

Article
What happened to Rio 2016's leftover food? Creative commons image Icon Indra Galbo under Creative Commons BY-NC-ND 4.0 license article icon

Health, Sports & Psychology 

What happened to Rio 2016's leftover food?

Gourmet chefs fed the athletes of the Olympic Games. Then, they fed the poor.

Article
Dukia Burges-Watson's diary Copyrighted image Icon Copyright: Photo courtesy of Lena Conlan and Vonna Keller for Hugging the Coast article icon

Nature & Environment 

Dukia Burges-Watson's diary

Dukia Burges-Watson from Hugging The Coast discusses her interest in environmental issues.

Article
Getting wasted… Creative commons image Icon By Ingorrr via Flickr under Creative Commons Licence under Creative-Commons license article icon

Nature & Environment 

Getting wasted…

Wendy Maples sifts through societal attitudes to waste, including the 'Freeganism' movement, an attempt to redress food wastefulness.

Article
OU/BBC Creative Climate short film competition 2011: Food for thought Copyrighted image Icon Copyright: The Open University video icon

Health, Sports & Psychology 

OU/BBC Creative Climate short film competition 2011: Food for thought

Dr Joe Smith introduces this short, engaging animation by /*-->*/ Gervais Merryweather, a student at the National Film and Television School. This simple animation unravels the relationship between food, trade and environment in the peel of an apple.

Video
5 mins
The politics of food: Perspectives Copyrighted image Icon Copyright: By Marcin Floryan via Wikimedia under Creative Commons 2.5 audio icon

Society, Politics & Law 

The politics of food: Perspectives

How does the decline of the British apple orchard have wider significance to our understanding of food, politics and the way we live? And why it is so important that the food activists have sustainable goals.

Audio
15 mins
Food for thought Copyrighted image Icon Copyright: The Open University video icon

Health, Sports & Psychology 

Food for thought

Architect, lecturer and author of 'The Hungry City', Carolyn Steel talks about her passion for the 'Dirt Cafe Sitopia' project, and how food can bring people together and shape our lives in the future.

Video
15 mins
Lucy Gilliam's story Creative commons image Icon Lego Activist / CC BY-NC 2.0 under Creative-Commons license article icon

Health, Sports & Psychology 

Lucy Gilliam's story

Explore the personal side of climate change with Lucy Gilliam's diary entry.

Article