Effect of gastric volume or emptying on meal-related symptoms after liquid nutrients in obesity: a pharmacologic study

Clin Gastroenterol Hepatol. 2005 Oct;3(10):997-1006. doi: 10.1016/s1542-3565(05)00285-5.


Background & aims: Altered postprandial satiation influences food intake in obesity. The aim of this study was to evaluate the contribution of gastric motor functions to intra- and postprandial symptoms in obese, otherwise healthy, people.

Methods: In a randomized, parallel-group, double-blind design, 40 obese (body mass index>30 kg/m2) healthy volunteers (n=10/group) received intravenous saline (placebo), atropine (.02 mg/kg), or erythromycin (1 or 3 mg/kg) to alter gastric volume and emptying after liquid nutrient meals, measured by validated imaging methods. The nutrient drink test assessed the volume ingested at maximum satiation, and intra- and early postprandial symptoms. Relationships between gastric motor functions, meal size, and symptoms were assessed by using multiple regression. Circulating levels of candidate upper-gut hormones involved in satiation were measured.

Results: Relative to placebo, atropine retarded gastric emptying and increased gastric volumes; erythromycin accelerated gastric emptying and reduced gastric volumes during fasting. Although similar maximal tolerated volumes were recorded across treatments, intra- and immediate postprandial symptoms were increased by these perturbations, particularly nausea and bloating. Upper-gut hormonal profiles generally reflected changes in gastric emptying. Regression analysis showed that fasting predrug gastric volume was a significant predictor of intra- and postprandial bloating. Change in gastric volume postdrug or postmeal did not contribute additionally to predicting intra- or postprandial symptoms. There was significant (negative) association between gastric emptying and fullness score, and significant (positive) association with hunger score 30 minutes postprandially.

Conclusions: In obese individuals, fasting gastric volumes and gastric emptying, but not postprandial gastric volumes, were associated with intra- and postprandial symptoms. Understanding the determinants of gastric volume may provide insights on mechanisms controlling satiation.

Publication types

  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Atropine / pharmacology
  • Double-Blind Method
  • Erythromycin / pharmacology
  • Female
  • Gastric Emptying / drug effects
  • Gastric Emptying / physiology*
  • Humans
  • Male
  • Middle Aged
  • Obesity / diet therapy*
  • Obesity / physiopathology*
  • Pancreatic Polypeptide / blood
  • Regression Analysis
  • Stomach / drug effects
  • Stomach / physiopathology*


  • Pancreatic Polypeptide
  • Erythromycin
  • Atropine