Q: I'm 15 years old, 5' and weigh around 107lbs. My RMR is around 1,338. Is that a poor, normal, or good RMR?

A: Don't worry about your RMR. I assume you used some kind of calculator where you plugged in your stats and daily activities and so on and it gave you back this number, right? If so, it's honestly pretty much a useless number and certainly nothing to stress about. Insted what you should worry about, especially at 15 years of age, is eating well (good nutritious foods, veggies, fruits) and getting at least 30 minutes of exercise every day through any kind of activity from walking to playing school sports to maybe even some moderate weight training under adult supervision. Take care of those things and RMR will take care of itself.