Like some others said, it depends on what stage you're in. If you want to loose much faster at a nice clip which gives incentive to continue, I think, I would totally avoid Oats being a starchy grain. I would wait until further down the line for beets and sweet potatoes.
There is really no difference in eating Oats or cereal out of a box or a piece of bread, it's all the same pure starchy carbs it will interfere with your weight loss and many people say it will take days to regain the momentum of weight loss.