title: Reproducibility of subjective appetite ratings and ad libitum test meal energy intake in overweight and obese males.
abstract: BACKGROUND
  To determine whether changes in appetite and energy intake (EI) can be detected and play a role in the effectiveness of interventions, it is necessary to identify their variability under normal conditions. We assessed the reproducibility of subjective appetite ratings and ad libitum test meal EI after a standardised pre-load in overweight and obese males.
  
  
  METHODS
  Fifteen overweight and obese males (BMI 30.3 ± 4.9 kg/m(2), aged 34.9 ± 10.6 years) completed two identical test days, 7 days apart. Participants were provided with a standardised fixed breakfast (1676 kJ) and 5 h later an ad libitum pasta lunch. An electronic appetite rating system was used to assess subjective ratings before and after the fixed breakfast, and periodically during the postprandial period. EI was assessed at the ad libitum lunch meal. Sample size estimates for paired design studies were calculated.
  
  
  RESULTS
  Appetite ratings demonstrated a consistent oscillating pattern between test days, and were more reproducible for mean postprandial than fasting ratings. The correlation between ad libitum EI on the two test days was r = 0.78 (P <0.01). Using a paired design and a power of 0.8, a minimum of 12 participants would be needed to detect a 10 mm change in 5 h postprandial mean ratings and 17 to detect a 500 kJ difference in ad libitum EI.
  
  
  CONCLUSIONS
  Intra-individual variability of appetite and ad libitum test meal EI in overweight and obese males is comparable to previous reports in normal weight adults. Sample size requirements for studies vary depending on the parameter of interest and sensitivity needed.
authors: School of Exercise and Nutrition Sciences, and Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia. Electronic address: katy.horner@chp.edu.
authors: Katy M
authors: KM
authors: Horner
authors: School of Exercise and Nutrition Sciences, and Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia.
authors: Nuala M
authors: NM
authors: Byrne
authors: School of Exercise and Nutrition Sciences, and Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia.
authors: Neil A
authors: NA
authors: King
mesh_terms: D000328:Adult; D001066:Appetite; D015992:Body Mass Index; D001835:Body Weight; D002149:Energy Intake; D005215:Fasting; D006801:Humans; D008297:Male; D062407:Meals; D008875:Middle Aged; D009765:Obesity; D050177:Overweight / Q000378:metabolism*; D064787:Portion Size; D019518:Postprandial Period; D011446:Prospective Studies; D015203:Reproducibility of Results
keywords: Ad libitum energy intake; Appetite; Obesity; Reproducibility; Test meal; Visual analogue scales