Should we ban super-size portions?

Eliminating larger-sized portions from the diet could reduce energy intake by up to 29%, according to a review that examined the links between ‘overserving’ and overeating.

The research, carried out by the University of Cambridge and published in the Cochrane Database of Systematic Reviews, 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 researchers combined results from 61 studies, capturing data from 6711 participants, to investigate the influence of portion, package and tableware size on food consumption.

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 1167 kJ per day) or by 22 to 29% among US adults (equivalent of up to 2205 kJ per day). The size of this effect was not found to vary 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, said that while it seems obvious that larger portions led to greater consumption, this was the first time the connection had been systematically examined. He said 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,” said Dr Hollands.

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.

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.”