Greek tortoises are going to primarily live off of plant food. Tortoises are herbivorous animals and shouldn’t be given animal products. However, giving Greek tortoises cuttlebone to gnaw on will help them get the calcium that they need in order to keep themselves healthy and strong. Giving almost any animal a variety of foods is a good idea, since different plants are going to vary in terms of the chemicals and nutrients that they contain. However, Greek tortoises only consume a fairly narrow range of foods, so that variety must be found within a relatively narrow category.