The measurement of gastric transit time in obese subjects using 24Na and the effects of energy content and guar gum on gastric emptying and satiety.

1. A new method has been used to measure mean gastric transit time. 2. This method, based on the absorption of 24Na from the proximal small bowel, is simple, non-invasive and can be used at the bedside. 3. The mean transit time was increased by adding guar gum to a test meal. 4. There was a significant correlation between mean gastric emptying time and a subjective measure of satiety.