70+ year old diet plan

[ROCK HARD 89]

ok so the other day i was with my grandpa and he asked me for a diet and i was like hmmm idk ill find out..

heres a little about him he dosnt lift weights he wakes up and stretches for 30 min everyday he dose a little cardio and is always always golfing.. hes about 5'10'' 180 pounds and he wants a good diet i guess to lean him up a little and to stay healthy any suggestions?

any help is appreciated thanks!