title: Perceptions of portion size and energy content: implications for strategies to affect behaviour change.
abstract: OBJECTIVE
  To assess Australian consumers' perception of portion size of fast-food items and their ability to estimate energy content.
  
  
  METHODS
  Cross-sectional computer-based survey.
  
  
  METHODS
  Australia.
  
  
  METHODS
  Fast-food consumers (168 male, 324 female) were asked to recall the items eaten at the most recent visit to a fast-food restaurant, rate the prospective satiety and estimate the energy content of seven fast-food or 'standard' meals relative to a 9000 kJ Guideline Daily Amount. Nine dietitians also completed the energy estimation task.
  
  
  RESULTS
  Ratings of prospective satiety generally aligned with the actual size of the meals and indicated that consumers perceived all meals to provide an adequate amount of food, although this differed by gender. The magnitude of the error in energy estimation by consumers was three to ten times that of the dietitians. In both males and females, the average error in energy estimation for the fast-food meals (females: mean 3911 (sd 1998) kJ; males: mean 3382 (sd 1957) kJ) was significantly (P < 0·001) larger than for the standard meals (females: mean 2607 (sd 1623) kJ; males: mean 2754 (sd 1652) kJ). In women, error in energy estimation for fast-food items predicted actual energy intake from fast-food items (β = 0·16, P < 0·01).
  
  
  CONCLUSIONS
  Knowledge of the energy content of standard and fast-food meals in fast-food consumers in Australia is poor. Awareness of dietary energy should be a focus of health promotion if nutrition information, in its current format, is going to alter behaviour.
authors: CSIRO Food and Nutritional Sciences - Adelaide, PO Box 10041, Adelaide BC, South Australia 5000, Australia. Emily.brindal@csiro.au
authors: Emily
authors: E
authors: Brindal
authors: Carlene
authors: C
authors: Wilson
authors: Philip
authors: P
authors: Mohr
authors: Gary
authors: G
authors: Wittert
mesh_terms: D000328:Adult; D001315:Australia; D001364:Awareness; D003430:Cross-Sectional Studies; D004435:Eating / Q000523:psychology*; D002149:Energy Intake / Q000502:physiology*; D057140:Fast Foods / Q000592:standards / Q000706:statistics & numerical data*; D005260:Female; D005502:Food / Q000145:classification*; D015438:Health Behavior; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D008297:Male; D011939:Mental Recall; D009753:Nutritive Value; D011446:Prospective Studies; D012527:Satiation