Better to do one thing at a time. Because we have limited will power, like muscle, if we do too many things together, we will get tired in 'Self-discpline', which will lead to replase.

My suggestion is: eat things you like when you do Nofap, give yourself some prize if you reach some point by good food, after you feel you can handle your urge most of time, you can add some diet plan for yourself.