depends on youer height. google, "body mass index."
Well little girl, I'll help you. http://www.nhlbisupport.com/bmi/ go there, enter you weight and height, and you'll see your bmi. Your body mass index, if you know what this means. In other words, if your normal weight is good for you.
600lb for all I know, you would have to give height and then all I could give you is a healthy weight ba<x>sed on BMI which doesn't account for lean muscle.
Depends on height, body type, etc.