You may be interested in the following links:

https://www.reddit.com/r/AskHistorians/comments/40diyv/what_was_the_roman_army_diet_and_exercise/ from u/rikalessandro

https://www.reddit.com/r/AskHistorians/comments/2tmhmx/what_did_the_diet_of_a_solider_in_the_early_roman/ from u/Celebreth

and

https://www.reddit.com/r/AskHistorians/comments/1nci3v/what_did_the_roman_legions_diet_consist_of/ from u/Celebreth again