My dad is 70years old. Having taste disorder and not much appetite. His feeling very weak and keep fainting. Has just brought him back from hospital but still feeling weak. He has already done CT scan and endoscopy for his intestine and nothing was found. Blood test only show that he lack of nutrition. This symptom has already being going on for 1 month. He use to be very health except that he had a heart attack once 5 years ago. And currently still on his medication.  When eat something sweet he feel very sweet and bitter become very bitter. And he is losing weight fast from 70kg to 60kg within a month. Im wondering what can i do to slowly help him recover his appetite?