Chewing and swallowing as indices of the stimulation to eat during meals in humans: effects revealed by the edogram method and video recordings.

Patterns of chewing and swallowing were recorded during standardized meals in humans. Cocktail size (3 cm2) open sandwiches were served in one of five different flavors. An oscillographic recording of chewing and swallowing showed that chewing activity varied with the palatability and variety of foods. Chewing time was shorter and fewer chews were observed as palatability increased. Swallowing did not change as a function of stimulus flavor. Pause duration between two successive food pieces became shorter as palatability increased. The effects of sensory factors were most evident at the beginning of meals and decreased until the end of meals. A later study which compared eating parameters in sandwich, semi-solid, and traditional French meals (different courses ingested in succession: appetizer, main course, cheese and dessert), as assessed from video recordings, found that different microstructure parameters responded to palatability manipulation in different meal types. Strength of mastication and prandial drinking might be other important parameters to look at in order to understand the motivation to eat and its fluctuations during the meal.