The portion size effect and overconsumption – towards downsizing solutions for children and adolescents

Abstract

Portion sizes of foods offered to consumers have increased at the same time as overweight and obesity levels have risen. It has been suggested that large portions of high energy density (HED) foods increase total energy intake and that this is not compensated for in the short-to medium-term, potentially promoting weight gain. In the laboratory setting, offering large portions of HED foods increases overall energy intake in both children and adults. This phenomenon is known as the portion size effect (PSE), and it is robust, reliable and enduring. The possible impact of the PSE is that large portions served over time may facilitate overeating and could contribute to overweight and obesity. Explanations for the PSE vary from simple heuristics, such as the tendency to clear the plate, to more complex biobehavioural processes, including individual differences in susceptibility to external food cues through eating traits. Consumers may eat in accordance with available consumption norms or eat opportunistically when large portions are made available. An obvious solution to the PSE is to 'downsize' HED meal items and snacks, but whether this strategy is acceptable or feasible is not clear. In adults, the effects of downsizing are mixed and for children and adolescents, as yet unclear. The contention is that for those who are still learning about social norms and appropriate portions, there remains the potential to counter the PSE through downsizing strategies.

Cultivating self‐regulatory eating behaviours during childhood: The evidence and opportunities

“…) and higher parent‐reported food responsivity (Kling et al . 2016a) have also been associated with a stronger PSE, suggesting that individual differences related to food approach behaviours are likely to underpin a child's sensitivity to larger portion sizes (Hetherington & Blundell‐Birtill ).…”

British Nutrition Foundation Annual Lecture 2017 – Diet, obesity and cardiovascular risk

“…), sometimes termed the ‘portion size effect’. However, it is not clear whether reducing portion sizes leads to reduced energy consumption at that meal and, if so, whether there is any compensatory increase in intake at subsequent meals (Hetherington & Blundell‐Birtill ).…”

“…There is considerable evidence that offering large portion sizes of energy-dense foods can lead to increased energy intake at that eating occasion (Hollands et al 2015), sometimes termed the 'portion size effect'. However, it is not clear whether reducing portion sizes leads to reduced energy consumption at that meal and, if so, whether there is any compensatory increase in intake at subsequent meals (Hetherington & Blundell-Birtill 2018).…”

Find your balance – the challenges of developing portion size guidance for the public

“…Numerous studies have shown that people of all ages, perhaps with the exception of very young children, eat more when portion sizes are larger (Hetherington & Blundell‐Birtill ) and it has been estimated that the effect of larger portion sizes across the diet in adults could be equivalent to a 12–16% increase in daily energy intake from food per day (Hollands et al . ).…”

“…Numerous studies have shown that people of all ages, perhaps with the exception of very young children, eat more when portion sizes are larger (Hetherington & Blundell-Birtill 2018) and it has been estimated that the effect of larger portion sizes across the diet in adults could be equivalent to a 12-16% increase in daily energy intake from food per day (Hollands et al 2015). In an economic analysis of cost-effective strategies to reduce obesity, portion size reduction (by food and drink producers, in restaurants and workplace canteens) was identified as the most cost-effective of 18 categories of intervention to help reduce obesity (McKinsey 2014).…”