At age 11, you only need to be concerned with dieting if your doctor says it's medically necessary. You're at the perfect age to begin to develop eating disorders and dysmorphic body image issues. My concern is that you're at the little seedling stages of that.
Also, keep in mind that the scale cannot show all the relevant numbers. There are a lot of factors you didn't mention. When thinking about what a healthy weight is for a particular individual, height is important. So are bone density, body frame, muscle and organ mass, and ethnicity... and hormonal issues. There are a multitude of factors that contribute to body weight, not just the amount of fat on the body.
Something is going to be "different" about you your entire life... because we're all different! I think the sooner you accept that and learn to love and accept yourself for who and what you are at any given moment, the better off you'll be. Letting others' opinions of you determine your self-esteem is so painful. Better to develop you're own inner strength. It is called "self"-esteem for a reason.
Answered Jun 08, 2011
Edited Jun 08, 2011