Originally Posted by
corporate-wage-slave
Congrats on the weight loss!
It's not really an issue from the UK Border arrival point of view, particularly if you use e-passport gates: staff are well trained to see how people change over time. If you changed gender or something then maybe.
Correct.
People who do facial recognition for a living (police, immigration, etc) are trained to look for the features which do not change (distance between eyes, for example). This is what the e-gates do: they pull out a set of invariate distance measures from the image of you standing there and compare with the same metrics stored on the embedded chip in your passport (determined from the photo you submitted printed on page 1).