Can't seem to loose on 1300-1500 cals per day

meghanner

I am a bit stumped. I recently put on a few pounds and would like to get back down to my previous weight of 108. I exercise very regularly burning between 400-900 calories a session. I eat rather clean and incorporate sea vegetables to help my thyroid. I don't eat a lot of carbs. What's up? I usually eat about 1300-1500 calories/day and have increased it trying to incorporate more carbs on days when I run a lot. Any suggestions?