How might postprandial ‘extras’ fatten? Simulation of a gastric mixing hypothesis

ABSTRACT It was suggested that the ingestion of extra calories towards the end of or shortly after a meal might be especially fattening. That hypothesis was based on the intuition that mixing of the sugared drink and accompaniments while the stomach was emptying rapidly would delay the release of hunger less than the same intake in the hour before the next meal. This paper presents an examination of that mechanism by calculating the time course of gastric emptying with extra intake at different times after the meal. The output from these simulations confirmed that early further energy would delay the end of emptying less than later. However, within the parameters tested, the effect is not large. Fattening effects of calories after meals could arise by a variety of mechanisms that remain to be tested without disrupting daily life. “Highlights” Extra intake may be more fattening shortly after meals than later. That proposal was supported by theoretical calculations of gastric emptying. Hence the timing of energy intake well before a meal seems critical to its effect on weight. The eater’s own concepts of meal, snacks and drinks are key to research on weight control.