Gastric emptying and ghrelin responses to oral nutritional supplements with varying protein content: a pilot crossover study in healthy adults

Description

Background & Aims
Oral nutritional supplements (ONS) are widely used in clinical practice, yet their effect on gastric emptying and appetite regulation may vary with composition. This study aimed to compare gastric emptying, subjective satiety, and exploratory ghrelin responses following ingestion of four drinks differing in protein and energy content.
Methods
In a single-center crossover study, five healthy adults (23–30 years) consumed four 200 mL drinks on separate days. Gastric emptying was assessed using the paracetamol absorption test (Tmax, AUC). Subjective appetite and sensory perception were evaluated using visual analogue scales (VAS). Serum total ghrelin was analyzed as an exploratory biomarker using ELISA at multiple time points up to 150 minutes.
Results
Low-protein drinks demonstrated significantly faster gastric emptying, with a shorter Tmax than high-protein drinks (p<0.05). No significant differences were observed in AUC or VAS-derived satiety scores. However, ghrelin responses differed between drinks. The high-protein drink (16 g/100 mL) induced the most pronounced and sustained suppression of ghrelin, whereas the low-protein drink (lower than 0.5 g/100 mL) showed only transient suppression followed by a marked increase at later time points. Intermediate responses were observed for drinks with moderate protein content (4.5-7 g/100 mL).
Conclusion
Protein and energy content influence gastric emptying and hormonal regulation of appetite. Although subjective satiety did not differ significantly, ghrelin responses suggest enhanced physiological satiety with high-protein formulations. These findings support the importance of considering both gastric emptying and hormonal mechanisms when designing ONS for clinical use.

Period	8 May 2026
Event title	Årsmøde i klinisk ernæring 2026: Dansk Selskab for Klinisk Ernæring (DSKE)
Event type	Conference
Location	Aarhus, DenmarkShow on map
Degree of Recognition	National