The role of a pre-load beverage on gastric volume and food intake: Comparison between non-caloric carbonated and non-carbonated beverage

Background: There is conflicting data on the effects of carbon dioxide contained in beverages on stomach functions. We aimed to verify the effect of a pre-meal administration of a 300 ml non-caloric carbonated beverage (B+CO ₂) compared to water or a beverage without CO₂(B-CO ₂), during a solid (SM) and a liquid meal (LM) on: a) gastric volume, b) caloric intake, c) ghrelin and cholecystokinin (CCK) release in healthy subjects. Methods. After drinking the beverages (Water, B-CO₂, B+CO₂), ten healthy subjects (4 women, aged 22-30 years; BMI 23 1) were asked to consume either an SM or an LM, at a constant rate (110 kcal/5 min). Total gastric volumes (TGV) were evaluated by Magnetic Resonance Imaging after drinking the beverage and at maximum satiety (MS). Total kcal intake at MS was evaluated. Ghrelin and CCK were measured by enzyme immunoassay until 120 min after the meal. Statistical calculations were carried out by paired T-test and analysis of variance (ANOVA). The data is expressed as mean SEM. Results: TGV after B+CO₂consumption was significantly higher than after B-CO₂or water (p <0.05), but at MS, it was no different either during the SM or the LM. Total kcal intake did not differ at MS after any of the beverages tested, with either the SM (Water: 783 77 kcals; B-CO₂: 837 66; B+CO₂: 774 66) or the LM (630 111; 585 88; 588 95). Area under curve of ghrelin was significantly (p <0.05) lower (13.8 3.3 ng/ml/min) during SM following B-CO₂compared to B+CO₂and water (26.2 4.5; 27.1 5.1). No significant differences were found for ghrelin during LM, and for CCK during both SM and LM after all beverages. Conclusions: The increase in gastric volume following a 300 ml pre-meal carbonated beverage did not affect food intake whether a solid or liquid meal was given. The consistency of the meal and the carbonated beverage seemed to influence ghrelin release, but were unable, under our experimental conditions, to modify food intake in terms of quantity. Further studies are needed to verify if other food and beverage combinations are able to modify satiation.