Rockstar has not announced a player-controlled weight, muscle, or body-change progression system for GTA 6. Character appearances and gym imagery cannot confirm a San Andreas-style mechanic on their own.
What imagery can and cannot prove
Official material may show characters exercising or people with varied body types. That demonstrates visual content, not a player progression mechanic.
What would change this answer
A Rockstar feature description, help page, or repeatable release-build test showing persistent player-driven change would provide the missing evidence.
Related entities
What we still don't know
- Whether workouts change stats
- Whether body shape can change
- Food and stamina interactions
