Larger portion sizes, packages and tablewear lead to the overconsumption of food

14 September 2015

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.

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.

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.

This 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, 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.”

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