title: Effect of reducing portion size at a compulsory meal on later energy intake, gut hormones, and appetite in overweight adults.
abstract: OBJECTIVE
  Larger portion sizes (PS) are associated with greater energy intake (EI), but little evidence exists on the appetitive effects of PS reduction. This study investigated the impact of reducing breakfast PS on subsequent EI, postprandial gastrointestinal hormone responses, and appetite ratings.
  
  
  METHODS
  In a randomized crossover design (n = 33 adults; mean BMI 29 kg/m(2) ), a compulsory breakfast was based on 25% of gender-specific estimated daily energy requirements; PS was reduced by 20% and 40%. EI was measured at an ad libitum lunch (240 min) and snack (360 min) and by weighed diet diaries until bed. Blood was sampled until lunch in 20 participants. Appetite ratings were measured using visual analogue scales.
  
  
  RESULTS
  EI at lunch (control: 2,930 ± 203; 20% reduction: 2,853 ± 198; 40% reduction: 2,911 ± 179 kJ) and over the whole day except breakfast (control: 7,374 ± 361; 20% reduction: 7,566 ± 468; 40% reduction: 7,413 ± 417 kJ) did not differ. Postprandial PYY, GLP-1, GIP, insulin, and fullness profiles were lower and hunger, desire to eat, and prospective consumption higher following 40% reduction compared to control. Appetite ratings profiles, but not hormone concentrations, were associated with subsequent EI.
  
  
  CONCLUSIONS
  Smaller portions at breakfast led to reductions in gastrointestinal hormone secretion but did not affect subsequent energy intake, suggesting small reductions in portion size may be a useful strategy to constrain EI.
authors.affiliation: Diet and Obesity Research, Medical Research Council Human Nutrition Research, Cambridge, UK.
authors.forename: Hannah B
authors.initials: HB
authors.lastname: Lewis
authors.affiliation: Diet and Obesity Research, Medical Research Council Human Nutrition Research, Cambridge, UK.
authors.forename: Amy L
authors.initials: AL
authors.lastname: Ahern
authors.affiliation: Diet and Obesity Research, Medical Research Council Human Nutrition Research, Cambridge, UK.
authors.forename: Ivonne
authors.initials: I
authors.lastname: Solis-Trapala
authors.affiliation: Diet and Obesity Research, Medical Research Council Human Nutrition Research, Cambridge, UK.
authors.forename: Celia G
authors.initials: CG
authors.lastname: Walker
authors.affiliation: Department of Clinical Biochemistry, Institute of Metabolic Science, University of Cambridge, UK.
authors.forename: Frank
authors.initials: F
authors.lastname: Reimann
authors.affiliation: Department of Clinical Biochemistry, Institute of Metabolic Science, University of Cambridge, UK.
authors.forename: Fiona M
authors.initials: FM
authors.lastname: Gribble
authors.affiliation: Diet and Obesity Research, Medical Research Council Human Nutrition Research, Cambridge, UK.
authors.forename: Susan A
authors.initials: SA
authors.lastname: Jebb
mesh_terms: D000293:Adolescent; D000328:Adult; D001066:Appetite / Q000502:physiology*; D018592:Cross-Over Studies; D004032:Diet; D002149:Energy Intake / Q000502:physiology*; D005260:Female; D005749:Gastric Inhibitory Polypeptide / Q000097:blood; D005768:Gastrointestinal Hormones / Q000097:blood*; D052216:Glucagon-Like Peptide 1 / Q000097:blood; D006801:Humans; D006815:Hunger / Q000502:physiology; D007328:Insulin / Q000097:blood; D008297:Male; D062407:Meals; D008875:Middle Aged; D050177:Overweight / Q000503:physiopathology*; D019894:Peptide YY / Q000097:blood; D064787:Portion Size; D019518:Postprandial Period; D011446:Prospective Studies; D055815:Young Adult
chemical_list: D005768:Gastrointestinal Hormones; D007328:Insulin; D019894:Peptide YY; D005749:Gastric Inhibitory Polypeptide; D052216:Glucagon-Like Peptide 1