Why is it that all my friends eat more than me, but I'm, like, way bigger?
- Hanifa*

Look around and you'll see lots of different body types — big body types, small body types, and everything in between.

The genes you inherit from your parents help determine your body type, but during puberty these differences seem even more exaggerated. At 13 years old, some people have already gone through their major growth spurt while others are just getting started. This might be one reason why you're bigger than your friends.

The best way to know if you're growing normally and at a healthy weight is to talk to your doctor, who can look at your growth over time and tell you the weight range that's right for you. Try not to compare yourself with those around you, but strive to be healthy by eating a balanced diet and being active every day.

Reviewed by: Mary L. Gavin, MD
Date reviewed: March 2011

*Names have been changed to protect user privacy.