I'm 17 years old. I'm 108 pounds, but the scale I use is broken, because it's a very old scale and sometimes my weight's wrong on it. I'm 5'8, and getting taller. I'm not anorexic or bulimic. I eat. A lot. I eat a lot of junk foods, but I never seem to gain weight. I eat a lot of peanut butter, whole grains, and other foods, but I never gain weight. I exercise to build up muscle, but if I don't exercise, I still won't gain any weight. I'm also Naturally Skinny.

What is wrong with me? Why can't I gain weight?

See your doctor, there might be a medical reason as to why you can't gain weight.

If you've tried diet and exercise, there's noting anyone on the internet can do to help you. You're only option is to find out why this is happening, and that requires a doctor.

Good luck.

Thank you :)