title: Effects of a preload on reduction of food intake by GLP-1 in healthy subjects.
abstract: OBJECTIVE
  Glucagon-like peptide-1 (GLP-1) inhibits food intake in animals and humans. Whether GLP-1 interacts with other satiety signals to modulate food intake is unknown. We investigated therefore in healthy volunteers the potential interactions of GLP-1 with signals from the stomach in regulating food intake.
  
  
  METHODS
  Three sequential, double-blind, crossover studies were performed in male subjects: (1) 12 subjects underwent four experiments (preloads) 20 min before meal intake; (2) 12 volunteers received intravenous (i.v.) GLP-1 (0.9 pmol/kg/min) or saline; (3) subjects received i.v. GLP-1 or saline (control) together with a preload of either 400 ml water or 400 ml protein shake. The effect of these treatments on food intake and feelings of hunger was quantified. Subjects were free to eat and drink as much as they wished.
  
  
  RESULTS
  GLP-1 induced a reduction in food and calorie intake (p < 0.005) compared to controls. If combined with a protein preload, the inhibitory effect of GLP-1 on food intake was markedly increased (p < 0.001). Furthermore, a decrease in hunger feelings and an increase in satiety feelings was documented.
  
  
  CONCLUSIONS
  GLP-1 interacts with signals from the stomach to modulate energy intake in humans. The signal is only initiated by nutrient-based distension, but not with gastric distension of the fundus alone.
authors.affiliation: Department of Research, Clinical Research Center, University Hospital, Basel, Switzerland.
authors.forename: Lukas
authors.initials: L
authors.lastname: Degen
authors.forename: Sibylle
authors.initials: S
authors.lastname: Oesch
authors.forename: Daniel
authors.initials: D
authors.lastname: Matzinger
authors.forename: Jürgen
authors.initials: J
authors.lastname: Drewe
authors.forename: Markus
authors.initials: M
authors.lastname: Knupp
authors.forename: Franziska
authors.initials: F
authors.lastname: Zimmerli
authors.forename: Christoph
authors.initials: C
authors.lastname: Beglinger
mesh_terms: D000328:Adult; D004435:Eating / Q000187:drug effects* / Q000502:physiology; D052216:Glucagon-Like Peptide 1 / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D012528:Satiety Response / Q000187:drug effects*; D013270:Stomach / Q000187:drug effects* / Q000502:physiology
chemical_list: D052216:Glucagon-Like Peptide 1