So I'm 17 years old and I keep losing weight or staying the same. I remember in December of 2014 I was like 117 lbs. and now I'm 101 lbs. also in like February of 2015 I started working out but not to lose weight I was building muscle, I'd only run for like 3 min and then use weights to squat or abs or arms for like 45 min. I stopped in like April though idk why. But I've been trying to gain weight since like end of summer and all I did was lose. My friends even noticed and are always mentioning how I'm getting so skinny and even my family too. I don't eat healthy I was wondering if that could be it because all I eat is junk food and people say that junk food would only make me gain but I don't really eat much real food. I love burgers and chicken and stuff but I don't really eat veggies or fruits and stuff. And I do get fuller faster now is it my stomach shrinking? Idk I just don't understand how I'm not even trying. Has anyone else had this or know about this?