About a year ago I started putting in effort to lose weight and get more physically active. My effort to lose weight was successful and I dropped about 13 pounds and felt great. But a few months ago I began doing more intense exersises and I started gaining weight instead even though I'm still eating less calories than what I need to stay the same weight. I'm just really confused because I haven't even been doing any weight training to build muscle and I use a calorie calculator so I don't ever eat enought to gain weight. Help?
There are so many variables, we can't really give a good answer to "why am I gaining weight despite eating less and working out more".
But, your plan sounds pretty good.. better than the average person. You're active, and you're feeding yourself well. I'd say as long as you're improving at your activity (running faster, kicking harder), keep up what you're doing.
Here are some reasons why you may not be noticing weight decrease: