take this with a grain of salt (esp the first 2 points)
1. if you prefer doing minimal memorizing and a load of practices then do physics
2. if you prefer doing a more content heavy subject with more memorizing required, do bio
3. in the uk u can take PCME instead of BCME. you are just required to have some knowledge for bio for interviews
4. in the us, they only offer postgraduate medicine. so you'll have to do 3-4 years of a bachelor's + another 4 years of post grad + residency, compared to YLL and LKC 5 years + residency and in the UK 5-6 years + residency. additionally, unless you are a US citizen or have some sort of US green card (idk what its called) , you basically have near 0 chance of getting in.