Soups increase satiety through delayed gastric emptying yet increased glycaemic response

Background/Objectives: Previous studies have demonstrated the satiating properties of soups compared with solids; however, the mechanisms controlling soup-induced satiety are unknown. This study aimed to understand the physiological mechanisms causing soup to be more satiating. Subjects/Methods: A total of 12 volunteers were tested on three occasions after a solid meal, chunky soup or smooth soup test meal for gastric emptying (GE) using the sodium [1-¹³ C] acetate breath test, satiety using visual analog scales (VAS) and glycaemic response (GR) using finger prick blood samples. Results: There was a significant difference in GE half-time (P=0.022) and GE ascension time (P=0.018), with the longest GE times for the smooth soup and the shortest for the solid meal. The GR area under the curve was significantly different between meals (P=0.040). The smooth soup had the greatest GR (87.0±49.5 mmol/l/min), followed by the chunky soup (65.4±48.0 mmol/l/min), with the solid meal having the lowest GR (61.6±36.8 mmol/l/min). Volunteers were fuller after the smooth soup compared with solid meal (P=0.034). Conclusions: The smooth soup induced greater fullness compared with the solid meal because of a combination of delayed GE leading to feelings of gastric distension and rapid accessibility of nutrients causing a greater glycaemic response.