Gastric capacity is related to body mass index in obese patients. A study using the water load test.

BACKGROUND The role of gastrointestinal function in obesity is unknown. Recent studies have shown that satiety in obese patients is influenced by an abnormal gastric capacity. AIM An easy and non-invasive tool, the water load test (WLT) was used to evaluate gastric capacity and how it relates to body mass index (BMI) in obese patients. METHODS The WLT was performed in 32 patients with high BMI and 12 healthy volunteers. Water was ingested at a 15 mL/min rate. The maximal tolerable volume (MTV) was defined as the total ingested volume when patients stopped the test. RESULTS A BMI > 30 was significantly associated with higher water consumption (2339 ± 306 mL) compared to controls (1830 ± 240 mL, p = 0.001). The MTV had a positive correlation with BMI (r = 0.68, p = 0.001). CONCLUSIONS Obese subjects have an increased gastric capacity, as measured with the WLT. This greater drinking capacity has a positive correlation with the subjects' BMI.