If you (the fairly experienced at foraging and trapping etc.) were to go on a long hike for, lets say, a few months and hiked across the more remote locations of Britain, would you be able to survive on merely hunting and foraging for food? Would there be enough to survive happily while getting enough healthy food and energy to continue with your hike?
No is the simple answer, not in the UK, as others have said, we are a small country and the climate won't help, there is just not enough year round wild food to give you a staple diet. I know one forum member here tried a three month UK stint, living off the land during the summer months, but still had to dig up farmers crops to keep himself going.