diff --git a/backend/models.py b/backend/models.py
index 86bdb8c..8025ca3 100644
--- a/backend/models.py
+++ b/backend/models.py
@@ -27,6 +27,7 @@ class ProfileUpdate(BaseModel):
     height: Optional[float] = None
     goal_weight: Optional[float] = None
     goal_bf_pct: Optional[float] = None
+    quality_filter_level: Optional[str] = None  # Issue #31: Global quality filter
 
 
 # ── Tracking Models ───────────────────────────────────────────────────────────