English Translation
I weigh about 60 kilos.
Unnatural… We hardly say およそ when we refer to our own weight because およそ is basically used to describe the approximately from an objective third-person’s view. およそ is more suitable for a weight of inanimate objects (i.e. stone, package) or of animals (i.e. meat).
私の体重は60キロくらいです。
私の体重は約60キロです。 Note: 約（やく）is more formal like “approximately” in English.
are more natural.
Note that およそ～、～くらい、約～ are also used for distance and required time etc.