[kh99]

It's pretty easy, if I understand what you're asking for. Just go to User Profile Fields in the admincp and create your fields. If you want the user to choose them you'd want Single-Selection Menu.

Then in the postbit (or postbit_legacy) template you just insert something like

Height: {vb:raw post.fieldX}<br/>
Weight: {vb:raw post.fieldY}

where the X and Y are the actual numbers for the height and weight fields you create (which you can see on the Profile Field Manager display).

This can also be done with a plugin to avoid editing the templates if you'd prefer that, you just need to add to one of the template hooks that are in the postbit. If you wanted the user to enter their data as text then check or format it, you'd need a plugin of course.