Eliminating larger-sized portions from the diet completely could reduce energy intake by up to 16% among UK adults or 29% among US adults, according to the research published in the Cochrane Database of Systematic Reviews.
Avoiding large portions was said to help consumers cut up to 279 calories from their daily diets.
The research was claimed to be “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.
‘Most conclusive evidence to date’
Overeating was known to boost the risks of heart disease, diabetes, and many cancers, which are among the top causes of ill health and premature death.
Co-leader of the report Dr Gareth Hollands said the research broke new ground.
“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,” said Hollands, from Cambridge University’s Behaviour and Health Research Unit.
There had been a tendency to blame overeating on personal factors, such as a lack of self-control, he added. “In fact, the situation is far more complex.
“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...”
- Ian Shemilt
‘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.”
The report was based on 61 studies, capturing data from 6,711 participants, to probe the influence of portion, package and tableware size on food consumption.
Overeating could be cut by imposing upper-limits on serving sizes of energy-dense foods and drinks and making larger portion sizes less accessible to shoppers. See more suggestive actions in the box below.
Research co-leader Ian Shemilt said: “At the moment, it is all too easy – and often better value for money – for us to eat or drink too much.
“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.”
More information is available here.
How to help people avoid overeating
- Impose upper-limits on serving sizes of energy-dense foods and drinks, for example, fatty foods, desserts and sugary drinks
- Limit the sizes of crockery, cutlery and glasses provided for use in their consumption
- Place larger portion sizes further away from purchasers to make them less accessible
- Distinguish single portion sizes in packaging through wrapping or visual cues