We propose a "protein and energy" free radical model of aging that predicts patterns of survival and fertility curves for Mediterranean fruit flies. Mathematical and simulation models of individual physiological processes were constructed in terms of stochastic differential equations. The free radical theory of aging was used as a basis for construction of the model and was extended to describe the dynamics of the protein and energy balance in the functioning organism, including the concept of a maximum capacity for energy production. We fit the model to observed patterns of survival and fertility in flies given the basic diet schemes used in respective experiments. Age patterns of fertility and survival were predicted under various diet scenarios using the model, revealing that the predictions of the model are in good agreement with experimental data.