Roman gladiators largely ate a vegetarian diet, which was mainly made up of barley and vegetables. Famous for being bloodthirsty combatants in the arena, gladiators were not great consumers of meat. However, this diet was based on utilitarianism, not idealism. The diet rich in carbohydrates helped gladiators develop power and endurance — the main advantage was the ability to gain weight and muscle mass. This was critical to their showing as gladiators, though, giving them extra protection in battle and a more striking appearance before the crowd.
As it turns out, gladiators were sometimes called "barley men," based on the significance of barley to their dietary regimen. Meals were oriented around packing them on — necessary both for survival and for spectacle. The average diet for gladiators was rich in starch, such as grains, legumes, plant-based foods and carbohydrates, consulte a doctor supplemented by occasional consumption of animal products, though these were not central to their meals. This regimen helped gladiators maintain the strength and resilience needed for the brutal combat they endured.
In addition to their plant-based diet, it is also noted that after training, gladiators consumed a tonic made from plant ashes, which was believed to help with recovery and maintain their physical condition.