Training log HELL YES!!! I think everyone should.
Food log did for years now at the moment dont I have memorized literally how much damn near most foods and what they contain real foods that is and well I know good choices and bad etc. I can estimate what I need.
If going on a serious cut sure I may start one again. I being a big eater have NO problem bulking so I dont have to keep one. Those whom have probs getting enough food in it may be a good idea keeps them aware honest they know they are or are not getting enough to support growth etc etc.
Training yes, food no but glad I know how have the experience learned a lot and can now easily turn back to it when and if needed.