title: Large portion sizes increase bite size and eating rate in overweight women.
abstract: OBJECTIVE
  Larger food portions lead to increased intake but the mechanism behind this effect is unclear. We investigated the effect of portion size on bite size, eating rate, deceleration rate, and meal duration.
  
  
  METHODS
  Thirty-seven overweight women attended 5 visits after a 3 h fast and consumed a 229, 303, 400, 529 or 700 g portion of a lunch meal in random order. Meal eating parameters were measured with the Sussex Ingestion Pattern Monitor. Data were analyzed with mixed effects models.
  
  
  RESULTS
  Average bite size increased by 0.22 g for every 100 g increase in portion size (p=0.001); portion size had a non-linear effect on eating rate, increasing with portion sizes up to about 540 g (p=0.01). Deceleration rate (reduction in speed of eating) decreased by 20% (p<0.001) and meal duration increased by 22.5% for every 100 g increase in portion size (p<0.001), relative to the smallest portion.
  
  
  CONCLUSIONS
  Increasing portion size led to a larger bite size and faster eating rate, but a slower reduction in eating speed during the meal. These changes may underlie greater energy intakes with exposure to large portions. Interventions to reduce bite size and slow eating rate may provide individuals with strategies to reduce the risk of overconsumption.
authors.affiliation: MRC Human Nutrition Research, Elsie Widdowson Laboratory, 120 Fulbourn Road, Cambridge CB1 9NL, UK.
authors.forename: Eva
authors.initials: E
authors.lastname: Almiron-Roig
authors.affiliation: MRC Human Nutrition Research, Elsie Widdowson Laboratory, 120 Fulbourn Road, Cambridge CB1 9NL, UK.
authors.forename: Melina
authors.initials: M
authors.lastname: Tsiountsioura
authors.affiliation: MRC Human Nutrition Research, Elsie Widdowson Laboratory, 120 Fulbourn Road, Cambridge CB1 9NL, UK.
authors.forename: Hannah B
authors.initials: HB
authors.lastname: Lewis
authors.affiliation: MRC Human Nutrition Research, Elsie Widdowson Laboratory, 120 Fulbourn Road, Cambridge CB1 9NL, UK.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Wu
authors.affiliation: MRC Human Nutrition Research, Elsie Widdowson Laboratory, 120 Fulbourn Road, Cambridge CB1 9NL, UK.
authors.forename: Ivonne
authors.initials: I
authors.lastname: Solis-Trapala
authors.affiliation: MRC Human Nutrition Research, Elsie Widdowson Laboratory, 120 Fulbourn Road, Cambridge CB1 9NL, UK; Nuffield Department of Primary Care Health Sciences, University of Oxford, UK. Electronic address: susan.jebb@phc.ox.ac.uk.
authors.forename: Susan A
authors.initials: SA
authors.lastname: Jebb
mesh_terms: D000293:Adolescent; D000328:Adult; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D008875:Middle Aged; D017711:Nonlinear Dynamics; D050177:Overweight / Q000523:psychology; D064787:Portion Size / Q000523:psychology; D012044:Regression Analysis; D013997:Time Factors; D055815:Young Adult
keywords: Bite size; Eating rate; Meal microstructure; Portion size