While you can benefit from yoga without making any other lifestyle changes but the discipline of yoga advocates a vegetarian diet. Yoga suggests a satvik diet that avoids any killing or harming of animals and encourages eating foods that are grown and ripened naturally. While your diet choice also depends on the goal of your yoga practice a yogic diet will work to improving your mind and body.
Different lifestyles work for different people and not all yogis embrace the concept of adopting a strict vegetarian diet. If yoga is a way only to keep your body toned, you do not need to force yourself to a vegetarian diet. Or if you are anaemic you may need to take supplements and eat meat. But if you cannot give up your love for non-vegetarian foods ensure that you eat them in moderation to get maximum benefits from your yoga practice.
Bottom line— Your diet is purely a matter of choice. However, remember to eat lean clean and green and avoid refined and junk foods as much as you can. Do not eat stale or overly cooked foods.