1. In this paper we show that analysis of changes in the distribution of stomach contents weights over time offers opportunities for improved understanding of fish feeding using data gathered from four of the larger fish species exploiting a sea-loch on the west coast of Scotland. 2. A simple dynamic model of the feeding and digestion process was developed to help understand complex feeding patterns, for which explanatory mechanisms are not immediately obvious. This model characterizes the 24-h cycle in food uptake rate by a small group of parameters whose values are estimated from the data set taken as a whole. 3. As a result of its higher immunity to noisy data, our model has advantages over previous methods for calculating food uptake rates