IMHO the fundamental issue is that the MOD has a responsibility to ensure that it's "troops" are fed correctly. Just the same as they provide Medical and Dental cover, nutrition is just as important if not more. If airman/soldiers/sailors are not eating correctly then they cannot possibly be at their fighting peak. Our men and women should not have the choice of not eating/eating cr@p. One of the worst things I have seen is women living on Pot Noodle and Irn Bru. Then we wonder why our people are de-motivated and have no energy.
I freely admit that a well run organisation can have a superb facility but Jack/Percy/Cyril will always rather spend his/her cash on beer instead. Take the money at source and they have less option.