That must feel very disheartening. This may sound stupid but have you got a cookbook giving photos of lamb, chicken etc, perhaps if you show him the recipe too as well as the photo he may remember the type of meat. I love fish and my husband with dementia wants meat and puddings all the time. I am a member of a slimming club as I like to stay slim, he is very thin and needs more calories, so I always cook 2 meals. It would feel so good to be appreciated but now I feel a little heartened when I hit on any form of success with food. At least he eats it which will do him good.