Answer: Low protein amounts
Explanation:
The human skin is made up of fats, water and protein with the most important protein being Collagen. Collagen is necessary for the body to heal its skin and nails and it uses it to reconstitute the damaged skin cells.
Meat provides an abundant source for proteins like collagen and because vegetarians like Jamie do not eat meat, they are denied this abundant source of protein such that they will be unable to heal their skin as effectively and as fast.