Anybody who is running 21 miles over the course of 48 hours in normal training probably doesn’t have any “unhealthy weight” to lose or probably much weight on them at all, period.
I’ve seen posts from OP before and I suspect at the very least some psychological issues with food are present, If you are running on average more than 10 miles a day then forget about calories all together. Unless you are spending the whole day binge eating there is absolutely no way you will put any significant weight on. Just eat, run, relax and repeat. Eat when you get hungry and make sure you have enough nourishment inside you for energy to train and do workouts. If you notice yourself actually putting on significant weight (which I doubt will happen) and feeling lethargic on your runs because of it then eat a diet of primary lean meats and vegetables for a week or two and you’ll be back in shape in no time.
One of the best things about being a semi-serious runner (40+ mpw) is that weight management is really easy so stop stressing.