title: Circulating ghrelin and GLP-1 are not affected by habitual diet.
abstract: BACKGROUND
  Ghrelin and glucagon-like peptide-1 (GLP-1) are gut hormones known to induce hunger and satiety, respectively. Current knowledge about the effects of different macronutrients on circulating ghrelin and GLP-1 comes mainly from acute test meals, whereas little is known about the effects of chronic dietary intake on gut hormone secretion. This study was designed to examine whether 8-week habituation to diets with different percentages of carbohydrate and fat would affect serum ghrelin, GLP-1, and subjective hunger in a postabsorptive state and in response to a standard liquid mixed meal.
  
  
  METHODS
  Sixty-one overweight men and women were provided all food for 8 weeks of either a higher-carbohydrate/lower-fat diet (High-CHO/Low-FAT; 55% CHO, 18% PRO, 27% FAT) or a lower-carbohydrate/higher-fat diet (Low-CHO/High-FAT; 43% CHO, 18% PRO, 39% FAT). After overnight fasts at baseline and week 8, participants consumed a standard liquid meal (7 kcals/kg, 58.6% CHO, 17.4% PRO, 24% FAT). Blood was sampled before the meal and at 15, 60, 90, 120, 180, and 240 min to determine total serum ghrelin and active GLP-1. Hunger was assessed by a visual analog scale. Mixed models were used to evaluate whether the temporal patterns of total serum ghrelin and active GLP-1 differed with diet.
  
  
  RESULTS
  Although both diet groups reported greater hunger after 8 weeks (p=0.03), circulating ghrelin and GLP-1 were not affected by acclimation to different macronutrients.
  
  
  CONCLUSIONS
  Habituation to different diets does not appear to influence fasting ghrelin, fasting GLP-1, or responses of these gut hormones to a standard meal.
authors.affiliation: Department of Nutrition Sciences at the University of Alabama at Birmingham, Birmingham, AL 35294-3360, USA. aellis04@uab.edu
authors.forename: Amy C
authors.initials: AC
authors.lastname: Ellis
authors.forename: Paula
authors.initials: P
authors.lastname: Chandler-Laney
authors.forename: Krista
authors.initials: K
authors.lastname: Casazza
authors.forename: Laura Lee
authors.initials: LL
authors.lastname: Goree
authors.forename: Gerald
authors.initials: G
authors.lastname: McGwin
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Gower
mesh_terms: D000328:Adult; D004032:Diet; D005247:Feeding Behavior; D005260:Female; D005768:Gastrointestinal Hormones / Q000097:blood; D054439:Ghrelin / Q000097:blood*; D052216:Glucagon-Like Peptide 1 / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D005768:Gastrointestinal Hormones; D054439:Ghrelin; D052216:Glucagon-Like Peptide 1