title: Visual exposure to large and small portion sizes and perceptions of portion size normality: Three experimental studies.
abstract: Portion sizes of many foods have increased in recent times. In three studies we examined the effect that repeated visual exposure to larger versus smaller food portion sizes has on perceptions of what constitutes a normal-sized food portion and measures of portion size selection. In studies 1 and 2 participants were visually exposed to images of large or small portions of spaghetti bolognese, before making evaluations about an image of an intermediate sized portion of the same food. In study 3 participants were exposed to images of large or small portions of a snack food before selecting a portion size of snack food to consume. Across the three studies, visual exposure to larger as opposed to smaller portion sizes resulted in participants considering a normal portion of food to be larger than a reference intermediate sized portion. In studies 1 and 2 visual exposure to larger portion sizes also increased the size of self-reported ideal meal size. In study 3 visual exposure to larger portion sizes of a snack food did not affect how much of that food participants subsequently served themselves and ate. Visual exposure to larger portion sizes may adjust visual perceptions of what constitutes a 'normal' sized portion. However, we did not find evidence that visual exposure to larger portions altered snack food intake.
authors.affiliation: Department of Psychological Sciences, Eleanor Rathbone Building, University of Liverpool, Liverpool, UK. Electronic address: eric.robinson@liv.ac.uk.
authors.forename: Eric
authors.initials: E
authors.lastname: Robinson
authors.affiliation: Department of Psychological Sciences, Eleanor Rathbone Building, University of Liverpool, Liverpool, UK.
authors.forename: Melissa
authors.initials: M
authors.lastname: Oldham
authors.affiliation: Department of Psychological Sciences, Eleanor Rathbone Building, University of Liverpool, Liverpool, UK.
authors.forename: Imogen
authors.initials: I
authors.lastname: Cuckson
authors.affiliation: Nutrition and Behaviour Unit, School of Experimental Psychology, University of Bristol, UK.
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Brunstrom
authors.affiliation: Nutrition and Behaviour Unit, School of Experimental Psychology, University of Bristol, UK.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Rogers
authors.affiliation: Department of Psychological Sciences, Eleanor Rathbone Building, University of Liverpool, Liverpool, UK.
authors.forename: Charlotte A
authors.initials: CA
authors.lastname: Hardman
mesh_terms: D000293:Adolescent; D000328:Adult; D015992:Body Mass Index; D001835:Body Weight; D002149:Energy Intake; D005260:Female; D006801:Humans; D008297:Male; D062407:Meals; D008875:Middle Aged; D064787:Portion Size; D011897:Random Allocation; D012858:Size Perception; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: Food selection; Norms; Portion size; Visual adaptation; Visual exposure