Effects of oral fructose and glucose on plasma GLP-1 and appetite in normal subjects

Peptides. 1999;20(5):545-51. doi: 10.1016/s0196-9781(99)00006-6.

Abstract

Oral glucose is a potent stimulant of glucagon-like peptide-1 (GLP-1) secretion. The effect of oral fructose on GLP-1 secretion in humans is unknown. The aims of this study were to determine (i) whether oral fructose stimulates GLP-1 secretion and (ii) the comparative effects of oral glucose and fructose on appetite. On 3 separate days, 8 fasting healthy males received, in single-blind randomized order (i) 75 g glucose, (ii) 75 fructose, or (iii) 75 g glucose followed by 75 g fructose I h later. Venous glucose, insulin and GLP-1 were measured. Appetite was assessed by visual analog questionnaires and intake of a buffet meal. Whereas glucose and fructose both increased plasma glucose, insulin and GLP-1 (P < 0.000)] for all), the response to glucose was much greater (P < 0.005 for all). There was no increase in plasma GLP-1 when fructose was given after glucose. There was no difference in food intake after oral glucose or fructose. We conclude that oral fructose (75 g) stimulates GLP-1 (and insulin) secretion, but the response is less than that to 75 g glucose. These observations suggest that neither GLP-1 nor insulin play a major role in the regulation of satiation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Appetite / drug effects*
  • Blood Glucose / analysis
  • Dietary Carbohydrates / pharmacology*
  • Fructose / pharmacology*
  • Glucagon / blood*
  • Glucagon / metabolism
  • Glucagon-Like Peptide 1
  • Glucose / pharmacology*
  • Humans
  • Hunger / drug effects
  • Insulin / blood
  • Male
  • Peptide Fragments / blood*
  • Peptide Fragments / metabolism
  • Protein Precursors / blood*
  • Protein Precursors / metabolism
  • Satiety Response / drug effects

Substances

  • Blood Glucose
  • Dietary Carbohydrates
  • Insulin
  • Peptide Fragments
  • Protein Precursors
  • Fructose
  • Glucagon-Like Peptide 1
  • Glucagon
  • Glucose