to gain weight or to gain muscle or lose weight by not eating

[nartuo4tail 6]

i was wondering if there be a system were u can build muscle in gym or gain weight if u eat too much or u can lose it like the system they did in gta san andreas were u can build up the muscle by going to gym or loseing muscle mass by not working out for some days?

[JamesLuck01 1,531]

@nartuo4tail Again please search or use the resources because this has been answered in the past.

1. this has been confirmed, gyms are in the world but at launch this won't be affected by the gym as it will be a feature which won't make it on full game release and will be added in future minor updates.