Mathematical Modeling of Behavior-Induced Body Weight Changes

We formulate a short-term (minutes) stochastic model of the factors affecting food intake. The model incorporates the interplay of glycemia, insulinemia and appetite to determine the size ofmeals and the probability of snacking. Simulations show the plausibility of the described food intake dynamics over the course of several years. Using themodel, we showcase two main situations: maintenance of a constant (lean) body habit, given healthy food choices; and rapid increase in body weight if sugary snacks and drinks are preferred, even when all other model parameters are kept unchanged (appetite, meal caloric offering etc.). The model is able to link minute-by-minute behavior with long-term changes in body weight and metabolic compensation, including increasing insulin resistance and increased variability of glycemia. Model simulations support quantitalively the hypothesis of a possible mechanistic pathway from alimentary lifestyle to Impaired Fasting Glucose and Impaired Glucose Tolerance and eventually to overt Type 2 Diabetes Mellitus.