No its not. I remember reading a British study some three years ago establishing the claim that starving cells can help boost cell regeneration, which is why old people are advised not to eat a lot since their cell regeneration rate is the lowest and they can use any boost they can get.
Yes, it is. When you starve your body you force it to eat whatever it can from your stores(fat and muscle). That isn't healthy.
I don't know what backwards ass medicine you're thinking of but I have NEVER heard any doctor tell an elderly person to eat less. Never. I have three doctors in my family(two uncles and an aunt) and they always tell my grandfather he needs to eat more, not less.