Appetite hormones and energy intake in obese men after consumption of fructose, glucose and whey protein beverages

Int J Obes (Lond). 2007 Nov;31(11):1696-703. doi: 10.1038/sj.ijo.0803665. Epub 2007 Jun 26.


Objective: To investigate appetite responses over 4 h to fructose beverages in obese men, relative to glucose and whey protein. Second, to investigate the effect of combining whey and fructose on postprandial appetite hormones.

Design: Randomized, double-blind crossover study of four beverages (1.1 MJ) containing 50 g of whey, fructose, glucose or 25 g whey+25 g fructose. Blood samples and appetite ratings were collected for 4 h then a buffet meal was offered.

Subjects: Twenty-eight obese men (age: 57.0+/-1.6 years, body mass index: 32.5+/-0.6 kg/m(2)).

Measurements: Plasma ghrelin (total), glucagon-like peptide-1 (GLP-1 7-36), cholecystokinin-8, glucose, insulin and appetite ratings were assessed at baseline and 30, 45, 60, 90, 120, 180, 240 min after beverages, followed by measurement of ad libitum energy intake.

Results: Fructose produced lower glycaemia and insulinaemia compared to the glucose treatment (P<0.0001); whereas postprandial ghrelin, GLP-1 and cholecystokinin responses were similar after both treatments. Whey protein produced a prolonged (2-4 h) suppression of ghrelin (P=0.001) and elevation of GLP-1 (P=0.002) and cholecystokinin (P=0.003) that were reduced when combined with fructose, while glucose and insulin responses were similar. Energy intake after 4 h was independent of beverage type (glucose 4.7+/-0.2 MJ; fructose 4.9+/-0.3 MJ; whey 4.6+/-0.3 MJ; whey/fructose 4.8+/-0.3 MJ; P>0.05).

Conclusion: In obese men, fructose- and glucose-based beverages had similar effects on appetite and associated regulatory hormones, independent of the differing glycaemic and insulinaemic responses. The contrasting profile of plasma ghrelin, GLP-1 and cholecystokinin after whey protein consumption did not impact on ad libitum intake 4 h later and was attenuated when 50% of whey was replaced with fructose.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Appetite / drug effects
  • Beverages*
  • Blood Glucose / metabolism
  • Cholecystokinin / blood
  • Cross-Over Studies
  • Dietary Carbohydrates / pharmacology*
  • Double-Blind Method
  • Energy Intake / drug effects*
  • Fructose / pharmacology
  • Ghrelin / blood
  • Glucagon-Like Peptide 1 / blood
  • Glucose / pharmacology
  • Humans
  • Insulin / blood
  • Male
  • Middle Aged
  • Milk Proteins / pharmacology*
  • Obesity / blood
  • Obesity / physiopathology*
  • Peptide Fragments / blood
  • Peptide Hormones / blood*
  • Whey Proteins


  • Blood Glucose
  • Dietary Carbohydrates
  • Ghrelin
  • Insulin
  • Milk Proteins
  • Peptide Fragments
  • Peptide Hormones
  • Whey Proteins
  • cholecystokinin 8
  • Fructose
  • Glucagon-Like Peptide 1
  • Cholecystokinin
  • Glucose