Sometimes, I still go through the "what's going to taste good today" routine. For me the cooking smells set the tone. On several occasions I had my wife stop cooking (even microwaving) due to the smell as I wouldn't eat it when finished. I have found out some of my favorites before chemo are barely tolerable still (chicken breast is one). My ONC says calories count, even the not so healthy ones when weight an appetite are an issue. During my worst days, ice cream, crackers, tuna, banana, salad, some cereals, pasta, nuts, raw veggies, and turkey were my goto. Luckily, my smell and taste have improved after stopping Folfox (even being on Folfiri now) and pretty much eat anything again.
Before dinner prep starts, somedays I do request something else or just fend for my self when something doesn't sound good. I still go through taste swings every once in awhile. Today veggies are great, next week no thanks. Same for meats, nuts, fruits, etc. We try to have several options on hand (including frozen) and a lot of times just the simple act of my wife mentioning 2-3 things will run across something that sounds good and is tasty.
P.S. With the mouth sores, if he's using the magic mouth wash that may affect his taste for the good or bad depending and how close to a meal he's using it.
56yo male DX 5/17, Right Hemi colectomy 6/17
Stage 3c 12 of 21 LN
7/17-12/17 Folfox(no Oxi round 9-12)
12/17 liver/lung mets-Stage 4 MSS KRAS G13D
2/18 liver doubled to 8.5cm+new met, lung mets to 1.4cm, multi peri/omen
2/18-7/18 Folfiri+Avastin(no 5FU after C2)
4/18 mets shrinking
7/18 liver/lung mets growing, Folfiri stopped
10/18 In Clinical Trial
CEA 5/17-16.2, 12/17-16.1, 02/18-43.0, 3/18-16.9, 4/18-9.0, 5/18-5.5, 6/18-6.9, 7/18-7.8, 9/18-56