Day-to-day reproducibility of, and relationships between, energy intake, gastric emptying and plasma CCK and GLP-1 in healthy lean males.

Abstract

Gastric emptying and intragastric distribution of a meal, and gastrointestinal hormones, including cholecystokinin (CCK) and glucagon-like peptide-1 (GLP-1), play an important role in appetite regulation. Healthy, lean, young males have widely been used in studies evaluating energy intake. It has, however, been reported that there is marked inter-individual variability in energy intake in this group. Whether there is significant intra-individual variation in acute energy intake after a nutrient preload, and, if so, this relates to changes in gastric emptying and gastrointestinal hormone release, is unclear. We hypothesised that appetite/energy intake after a nutrient preload would be reproducible and associated with reproducible patterns of gastric emptying and gastrointestinal hormone release. 15 healthy males consumed a glucose preload (50 g glucose in 300 ml water; 195 kcal) on 3 separate occasions. Gastric emptying and intragastric meal distribution (measured by 3D ultrasound), plasma CCK and GLP-1 and appetite perceptions were evaluated over 90 min, after which energy intake from a cold, buffet-style meal was quantified. Energy intake (kJ) and amount eaten (g) showed excellent agreement between visits (intraclass correlation coefficient, r i >0.8), while for macronutrient distribution, reproducibility was moderate to good (0.54< r i <0.77). Furthermore, patterns of gastric emptying, intragastric meal distribution and appetite perceptions did not differ (all P <0.05), and areas under the plasma CCK and GLP-1 curves also showed excellent agreement ( r i >0.8), between days. Therefore, in healthy males, patterns of gastric emptying and gastrointestinal hormone secretion are highly reproducible, when measured repeatedly on separate occasions, and associated with reproducible energy intakes.