How Weight Changes the Face
Weight changes redistribute facial fat, primarily affecting the cheeks, jawline definition, and the thickness of soft tissue structures around the eyes and midface. At high body weights, fuller cheeks can appear to reduce inter-cheekbone distance and reduce the apparent definition of bony facial features. At lower body weights, bony structure becomes more prominent and facial geometry more closely matches the bony skeleton.
The bony skeleton, the basis for the most stable components of a facial embedding, does not change with weight. But the soft tissue overlay can change substantially, altering the apparent geometry of features and shifting the facial embedding toward or away from different regions of face space.
Practical Effect on Matching
For modest weight changes, the effect on celebrity matching is usually small. The embedding is robust to typical soft tissue variation because the network has been trained on faces across a wide range of healthy body weights. For large weight changes (30+ kg / 65+ lbs), the soft tissue changes become large enough to noticeably shift the embedding.
People who have lost significant weight often report that their celebrity matches change, typically toward celebrities with more defined bony features. This reflects a genuine shift in facial geometry rather than a recognition error.