Mathematical determination of feeding patterns and its consequence on correlational studies

The literature contains discrepancies on the definition of parameters of feeding pattern and, consequently; on the relation between the size of a meal and the interval that precedes and follows it. In this paper, based on 1513 meals recorded on 22 rats, we used a modified method to set up the parameters of ingestive behavior based on one main principle: no parameter had to be pre-defined before the raw data were processed. Then, the characteristics of the meal, meal duration, meal size, intra-meal pauses, inter-meal intervals, and rate Of ingestion were determined. Once the characteristics of the meal were set up, our method was experimentally validated by offering scheduled meals. Depending on the ingestion rate, three classes of meals were also identified: slow-, medium-, and fast-rate meals. i.e., there were individuals who tended to eat slowly while others ate faster. Besides validating the proposed method, the collected data were also used to revisit the question concerning the post-prandial correlations. The correlations between meal size and the pre or post-prandial intervals weren't confirmed. However, when we applied to our own data previous methods of analysis based on arbitrary criteria used by other authors, we verified those correlations. By reinforcing the principle of using raw data and objective criteria to define feeding behavior parameters, this study allows to further consider the meal-to-meal relations and raises the problem of the interpretation of such relations in terms of their physiological significance. (C) 1998 Elsevier Science Inc.