Role of Non-Caloric Carbonated Beverage Preload During a Standardized Solid and Liquid Meal on Colecistokinin and Ghrelin Levels in Healthy Subjects

Background and Aim: The effects of beverages with carbon dioxide on the gastrointestinal system mainly involve the upper digestive tract, with a possible modification of gastric physiology and change in food intake. No data are available on the relationship between non caloric carbonated beverages intake and gastrointestinal hormones levels. We aimed to verify the effect of a sugar-free carbonated beverage (CB) preload compared to a CB without CO2 (DCB) and water (W), during a standardized solid (SM) and liquid (LM) meal, on colecistokinin (CCK) and ghrelin (Gh) release. Subjects & Methods: After 300 ml of CB, DCB and W, a standardized SM or LM was administered at constant rate (100 kcal/5 min) to ten healthy subjects (4 females, aged 22-30 years; BMI 21-24) on six days in a random order (D1: CB+SM; D2: DCB+SM; D3: W+SM; D4: CB+LM; D5: DCB+LM; D6: W+LM). Eating perceptions (desire to eat, hunger, prospective of food consumption) and maximum satiety (MS) as total kcals intake were measured. CCK and Gh were evaluated on blood samples collected at 0, 10 (after beverage), 30, 60 and 120 min. Hormones values are expressed as ratio with body area surface (BSA) and as peak and nadir for CCK and Gh respectively. All data are expressed as mean±SD. Results: Desire to eat, hunger and prospective of food consumption were not different among beverages and meals. Total kcal intakes at MS were significant increased during SM respect to LM for CB (774±209, 585±299, p<0.01), DCB (837±208, 585±280, p<0.01) andW(783±244, 630±353, p<0.01) respectively, without differences among beverages. No differences were found for CCK and Gh among all beverages during SM or LM. Instead, CCK after CB was higher during SM than LM (1.004±0.514, 0.513±0.243, p<0.05) but not after DCB and W (0.790±0.604, 0.849±0.595, n.s.; 0.712±0.473, 0.873±0.431, n.s.) respectively. Moreover, after all beverages, Gh was higher during SM than LM (CB: 0.314±0.100, 0.206±0.099, p<0.05; DCB: 0.288±0.060, 0.145±0.051, p<0.01; W: 0.307±0.083, 0.170±0.085, p<0.01). Conclusions: Liquid meal determined an earlier satiety respect to a solid meal with a parallel decrease of Ghrelin independently of the kind of beverage preload. A CCK decrease was found only during liquid meal after carbonated beverage preload without influence on kcal intake compared with DCB and W. Studies on the influence of carbon dioxide on CCK release nutrients related need to explain this data.