Thanks for posting your query.
With the available described symptoms, there appears to be high possibility of Non alcoholic steatohepatitis
(NASH) induced chronic liver disease
Presence of diabetes
and deranged liver function with already diagnosed history of CLD suggests the diagnosis.
You should consult with internal medicine specialist/ gastroenterologist and should go for thorough check up.
He must have some degree of portal hypertension
as he has CLD with deranged liver function test.
He can take Liquid Aptivate for increasing appetite.
Other appetizer available in markets contains cyproheptadine
which has some sort of sedative effects; avoidable in liver disease.
He should take normal diet.
Aptivate and normal diet will help your father.
Dr. Mayank Bhargava