Carrots are one of just a few vegetables that may actually become MORE nutritious when cooked. While the cooking process can reduce the vitamin C in the carrots, it can increase the availability of their carotenoids (a powerful antioxidant), which are converted to vitamin A and benefits hair, heart, and eye health. Carrots cooked whole (especially when boiled) will also help increase the nutrients (as opposed to dicing them). In terms of which is better, I think both are relatively similar when cooked whole. However, I prefer the texture and flavor of roasted carrots, making them the winner for me.