While I wouldn't say your workouts are on quite the same level, when my mom was a swimmer (lifeguard, personal trainer, competitive swimmer, and swim instructor all at once), she was eating about 3,000 calories a day just to keep from falling over- technically she should have been eating 4,000 calories but just couldn't make the time for so much food. One thing that she taught me is that if you're trying to gain muscle, a calorie deficit is a huge mistake. If you were just trying to burn fat, sure, but your body CAN'T get any bigger unless there are calories to use to build up your muscle. Usually you only need a deficit with gaining if you're A) working to be a body builder and you need to cut or B ) you're extremely overweight and the weight loss could be life saving. Since I'll guess neither is the case, you need to be eating more than you burn to gain muscle, especially since just having muscles burns more calories at rest. So as you gain muscle, your resting metabolism is going to raise and you'll need to eat more than you used to. Mine and my mom's go-to meal if we're having trouble eating enough is rice and beans with baked or grilled chicken and sliced banana. It's filling, full of protein, and gives you plenty of good energy to workout and for your body to repair itself.