Though dogs have adapted to a domesticated, omnivorous diet over the centuries, a protein-based diet free of grains more closely mimics their ancestral beginnings. Dogs are able to digest grains, but their bodies don't break down grains as efficiently as they do proteins and fats. This is why a diet free of grains and made with limited protein sources is an excellent option for all dogs, but especially for those with food sensitivities. The first ingredient in every formula of Diamond Naturals Grain-Free is animal-sourced protein from trusted sources, for superior taste and nutrition. Sweet potatoes provide complex carbohydrates for all-day energy, while fruits and vegetables add powerful natural antioxidants for optimal health and vitality.