why is my abdomen shrinking but scale not moving?

Dianakrugle

So the scale hasn't moved but this week my abdomen shrunk 1 1/2 inches? My back has lost its fat rolls and my abdomen is smaller. Nothing else much has changed. Still unable to eat enough 800-1000 calories if lucky, and constant migraines and nausea, ( seeing a neurologist), but why am I shrinking? Also I went from 5'4" to 5'3"?