Dawmrichy when I first quit drinking I ate really high carb for the first six months. Lots of sugar, ice cream, candy, etc. To me, it helped a lot with cravings.
I feel like that was a normal transition for me. I knew to cut back as soon as I could, but I had been tracking food and macros for many years before I quit drinking. The carb preference died a natural death for me.
I'd say let your friend find his own way - what works for one may not work for others. It's his journey and he has to decide.