Grain-free pet food removes traditional grains (corn, wheat, soy, rice, barley, oats), typically replacing them with peas, lentils, chickpeas, potatoes, or sweet potatoes. The category exploded after grain allergies were popularly (but largely incorrectly) blamed for skin and digestive issues. The 2018 FDA DCM investigation has tempered the grain-free movement among veterinary nutritionists. Grain-free is appropriate for confirmed grain allergies but not the safer default it was once marketed as.