I feel I must go out on a limb with this a bit. Too many Alzheimer's patients have spent many years being isolated and lonely, have suffered the trauma of losing their spouse or significant other, have few if any hobbies, or otherwise feel like they have little to live for except watching endless amounts of TV with a bowl of ice cream or plate of cookies close at hand.
There is also sufficient evidence to suggest that early stage Type 3 Diabetes (and therefore most Alzheimer's Disease) can be easily reversed if caught soon enough with exercise, insulin and more moderate sugar consumption. Going for a walk three times a week is enough to make a big difference in someone who is excessively sedentary. Making it a rule never to eat sugar on an empty stomach or substituting more protein and fat and fewer carbohydrates can make a big difference right away regardless of the amount of exercise. And try arranging it so your loved one takes that walk and eats that meal with someone who loves them! That could make the biggest difference in quality of life for both the patient and all concerned.