Description of chewing and food intake over the course of a meal

While the average frequency of chewing and food intake have been reported before, a detailed description of the pattern of chewing and the cumulative intake of food over the course of a meal have not. In order to achieve this goal, video recording of the maxillary-mandibular region of women eating food from a plate was synchronized with video recording of the plate and computer recording of the weight-loss of the plate. Video recording of chewing correlated strongly with chewing identified by magnetic tracking of jaw displacement in a test with chewing gum at three different frequencies, thus ensuring the validity of video recording of chewing. Weight-loss data were corrected by convolution algorithms, validated against human correction, using sliding window filtering to correct errors with video events as reference points. By use of this method, women ate on average 264 g of food over 114 min, they took an average of 51 mouthfuls during the meal and displayed on average 794 chews with 15 chews per chewing sequence. The number of mouthfuls decreased and the duration of the pauses after each mouthful increased in the middle of the meal and these measures were then restored. The ratio between chewing sequences and subsequent pauses remained stable although the weight of each mouthful decreased by the end of the meal, a measure that is hypothesized to be reflected in a decelerated speed of eating. The method allows this hypothesis to be tested and its implication for clinical intervention to be examined. (C) 2011 Elsevier Inc. All rights reserved.