Effect of caloric density of a meal on lower oesophageal sphincter motility and gastro-oesophageal reflux in healthy subjects

Background: Patients with gastro-oesophageal reflux disease are advised to avoid the ingestion of large meals. In healthy volunteers, a relationship b etween the amount of postprandial gastro-oesophageal reflux and the volume of a liquid meal has been demonstrated. Aim: To evaluate whether the amount of postprandial gastro-oesophageal refl ux is also related to the calorie content of a meal, a second parameter tha t will be reduced by avoidance of the ingestion of large meals. Methods: Twelve healthy volunteers (six female, 19-31 years) received two s olid-liquid meals with either 842 kcal (solid 582 kcal, liquid 260 kcal) or 582 kcal (31% reduction) in a randomized order. The nutritional components (10% fat, 76% carbohydrates, 14% protein) and the volume of the meals were identical in both meals. The lower oesophageal sphincter pressure was meas ured continuously in the first postprandial hour with a Dent sleeve, and pH -metry was performed for 3 h postprandially with a glass electrode in the d istal oesophagus. Blinded to the type of ingested meal, we calculated the m ean lower oesophageal sphincter pressure, the frequency of transient lower oesophageal sphincter relaxations, the number of reflux episodes, and the f raction of time for which pH < 4. Results: A similar decrease in lower oesophageal sphincter pressure was obs erved after ingestion of the high calorie meal (median 10.9 mmHg, range 4.8 -16.7 mmHg) and low calorie meal (median 9.9 mmHg, range 3.9-18.4 mmHg). No difference in the number of transient lower oesophageal sphincter relaxati ons (high calorie: median 9 per hour, range 5-13 per hour; low calorie: med ian 7 per hour, range 0-14 per hour) and of reflux episodes (high calorie: median 12 in 3 h, range 3-22 in 3 h; low calorie: median 12 in 3 h, range 3 -30 in 3 h) was registered after intake of both types of meal. Additionally , no difference was identified regarding the fraction of time for which pH < 4 between the high calorie (mean 2.3%, 0.2-23.7%) and low calorie meal (3 .3%, 0.5-17.8%). Conclusion: Reducing the caloric density of a meal neither influences postp randial lower oesophageal sphincter pressure nor decreases gastro-oesophage al reflux in healthy volunteers. Thus, the amount of gastro-oesophageal ref lux induced by ingestion of a meal seems to depend on the volume but not on the caloric density of a meal.