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Portion, package or tableware size for changing selection and consumption of food, alcohol and tobacco (Review)
Hollands GJ, Shemilt I, Marteau TM, Jebb SA, Lewis HB, Wei Y, Higgins JPT, Ogilvie D (2015)
"1) To assess the effects of interventions involving exposure to different sizes or sets of physical dimensions of a portion, package, individual unit or item of tableware on unregulated selection or consumption of food, alcohol or tobacco products in adults and children."
"2) To assess the extent to which these effects may be modified by study, intervention and participant characteristics."
Findings
The authors state:
"Ninety-six per cent of included studies (69/72) manipulated food products."
"Forty-nine per cent (35/72) manipulated portion size, 14% (10/72) package size and 21% (15/72) tableware size or shape.”
“all studies were conducted in high-income countries - predominantly in the USA (81% (58/72)).”
"all included studies were randomised controlled trials."
"The majority of included studies were conducted in laboratory settings (50 of 72).”
“22 of 72 were conducted in field settings - predominantly restaurants or school or workplace cafeterias"
“Consumption outcomes only were reported in 59 of 72 included studies.”
“Selection outcomes only were reported in seven other studies, whilst both selection and consumption outcomes were reported in six other studies.”
"Outcomes were measured objectively rather than by participant self-report in almost all included studies with two exceptions, and were typically measured over a period of one day or less (60 of 72 studies)."
"A meta-analysis of 86 independent comparisons from 58 studies (6603 participants) found a small to moderate effect of portion, package, individual unit or tableware size on consumption of food (SMD 0.38, 95% CI 0.29 to 0.46), providing moderate quality evidence that exposure to larger sizes increased quantities of food consumed among children (SMD 0.21, 95% CI 0.10 to 0.31) and adults (SMD 0.46, 95% CI 0.40 to 0.52)."
"The size of this effect suggests that, if sustained reductions in exposure to larger-sized food portions, packages and tableware could be achieved across the whole diet, this could reduce average daily energy consumed from food by between 144 and 228 kcal (8.5% to 13.5% from a baseline of 1689 kcal) among UK children and adults."
Twelve field studies were in adults.
Conclusions
The authors state:
"This review found that people consistently consume more food and drink when offered larger-sized portions, packages or tableware than when offered smaller-sized versions. This suggests that policies and practices that successfully reduce the size, availability and appeal of larger-sized portions, packages, individual units and tableware can contribute to meaningful reductions in the quantities of food (including non-alcoholic beverages) people select and consume in the immediate and short term. However, it is uncertain whether reducing portions at the smaller end of the size range can be as effective in reducing food consumption as reductions at the larger end of the range."
"it is important to highlight that the sustainability of effects remains to be established, since studies included in this review were limited to the investigation of one-off or repeated exposures over short time periods (periods of 1 day or less)."
"results suggest that intervening to reduce exposure to larger sizes of portions, packages, individual units or tableware may be more effective in influencing food consumption among adults than among children."
"These findings highlight the current lack of evidence to establish whether meaningful changes in the quantities of food people consume can be sustained over the longer term in response to prolonged or repeated exposures, under free-living conditions."
