How to know if you are overweight, normal, or underweight?

Find a: Chart on the internet listing recommended heights/weights for each sex and various ages. There are also multiple phone apps which give the same information.

Why do you ask?: Dr. Snead is right about the charts, but why the concern? You're a person, not a number, and if you feel well, there's no benefit in targeting a number instead of aiming for general fitness. Many elite track-and-field athletes are "underweight" while lean, solid football linebackers are "obese". If you're competitive in your favorite sport, and comfort with your body, you're probably fine.