title: Ghrelin but not peptide YY is related to change in body weight and energy availability.
abstract: OBJECTIVE
  The aim of this study was to examine changes in fasting total peptide YY (PYY) and ghrelin in nonobese premenopausal women after an exercise and diet program with and without weight loss.
  
  
  METHODS
  Body composition, energy balance parameters, ghrelin, and PYY were measured before and after a 3-month intervention in nonexercising controls (n = 7) and exercising women who either remained weight stable (n = 5) or lost weight (n = 10). At baseline, subjects were 20.6 ± 2.2 yr, weighed 58.0 ± 4.8 kg, and had 27.2% ± 4.9% body fat. Supervised exercise training occurred five times a week for up to 90 min at 70%-80% of maximum HR. Subjects were fed a controlled diet.
  
  
  RESULTS
  Body weight (-3.2 ± 0.8 kg) and fat mass (-2.6 ± 0.7 kg) decreased significantly in the weight-loss exercise group. Neither fasting ghrelin nor PYY changed in response to exercise training in the absence of weight loss, and PYY did not change with exercise and weight loss. Fasting ghrelin did reveal a significant time × experimental group interaction (P = 0.025). The change in ghrelin was inversely correlated with the change in body weight, body mass index, fat-free mass, and energy availability.
  
  
  CONCLUSIONS
  Neither fasting ghrelin nor fasting PYY seem to play a role in the adaptive changes associated with exercise training when exercise occurs in the absence of weight loss. Fasting ghrelin concentrations increase when body weight is lost and may respond to even smaller changes in energy availability. However, fasting PYY does not seem to play a key role in the regulation of energy balance during diet- and exercise-associated weight loss.
authors.affiliation: Women's Health and Exercise Laboratory, Noll Laboratory, Department of Kinesiology, The Pennsylvania State University, University Park, PA 16802, USA.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Scheid
authors.forename: Mary Jane
authors.initials: MJ
authors.lastname: De Souza
authors.forename: Heather J
authors.initials: HJ
authors.lastname: Leidy
authors.forename: Nancy I
authors.initials: NI
authors.lastname: Williams
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D001835:Body Weight / Q000502:physiology*; D004032:Diet; D004734:Energy Metabolism / Q000502:physiology; D015444:Exercise; D005260:Female; D054439:Ghrelin / Q000097:blood*; D006801:Humans; D019894:Peptide YY / Q000097:blood*; D015431:Weight Loss / Q000502:physiology; D055815:Young Adult
chemical_list: D054439:Ghrelin; D019894:Peptide YY