12 January - 20 June 2016

Portion size and its influence on consumption

23 Oct 13

A substantial review of literature relating to studies of portion size and its influence on consumption is to appear in Critical Reviews in Food Science and Nutrition. It challenges the often quoted assertion that there has been an increase in portion sizes that has directly led to increased consumption and an increase in obesity. The review, written by David Benton of the Department of Psychology, Swansea University takes the stance that much of the evidence linking increased portion size to increased consumption comes from laboratory studies that are necessarily limited in their scope. He argues that the conclusions of such studies are limited by the complexity of the phenomenon and there is a need to consider meals freely chosen over a prolonged period when a range of foods of different energy densities are available. A range of factors will influence the size of the portion size chosen: amongst others packaging, labelling, advertising and the unit size and not simply the portion size of the food item.  Benton argues that further studies are needed to establish the way portion size interacts with the multitude of factors that determine food intake. He also notes that even if all evidence points to reduction of portion size as a viable strategy in preventing obesity, opposing factors such as perceived value for money, will still motivate consumers to opt for 'larger' items when faced with a choice at point of purchase.

This week the popular press have reported on a report commissioned by the British Heart Foundation that states that nearly two-third of UK adults are overweight or obese. The report compared portion size of 245 products with portion size listed in a 1993 government publication called “Food Portion Size.”  The report notes that “portion size of several products, including single serve packets of crisps, portions of corn flakes, and cheddar cheese, are all identical to the information provided twenty years ago.  Some products have portion sizes that are in fact lower now than in 1993– including ice creams.  However, this pattern is not reflected across the products analysed as a whole, with some showing considerable growth since 1993. In particular, certain bread products and all of the ready meals analysed showed substantial growth in portion size – as much as 98 per cent for one ready meal.”  The report states “manufacturers have moved away from the Government’s 1993 publication to the extent that this is no longer fit for purpose in helping retailers to size portions appropriately to reflect a 2013 portion size. As a result, this is making it difficult for consumers to compare products across different brands and control their portion sizes.”  The report makes a number of suggestions including that the government needs to provide guidance for industry to enable standardisation of portion sizes and guidance on what constitutes a healthy portion, working alongside health experts to produce this information.  It notes that food companies need to stop increasing the portion size of single unit foods and, in some cases, look to reducing sizes in adherence to new guidance, adopt the new front-of-pack food labelling scheme and ensure that portion sizes are standardised, clearly labelled and easy to understand, so the consumers can make healthy choices.

share this article
RSSL endeavours to check the veracity of news stories cited in this free e-mail bulletin by referring to the primary source, but cannot be held responsible for inaccuracies in the articles so published. RSSL provides links to other World Wide Web sites as a convenience to users, but cannot be held responsible for the content or availability of these sites. This document may be copied and distributed provided the source is cited as RSSL's Food e-News and the information so distributed is not used for profit.

Previous editions

Load more editions

Make an Enquiry