Query for Dad. Ans sleeping + 5 meals.

Med history: Chest Bypass surgery in February 2016, Ca right vocal cord Stage II T2, N0, M0 in April 2017, Radiotherapy treatment c1, VMAT Smoking- Ex smoker since 18 months Apparently he has been struggling with a silent acid reflux that first affected his ears. Later on his arteries and then vocal chords/throat. He is much better now, though he still jas cough and apparently under weight. I would like to try out a detox diet that helps him to deal with acid reflux in a better way. Or probably typical Do's and Dont's / lifestyle changes that can help to ease his condition and help him to recover faster. He's been told to use a wedge pillow, have 12 glasses of water and ensure a gap of 3 hours between meals ans sleeping + 5 meals. Thanks in advance