Your body can produce the energy from your fat stores, the brain runs better on ketones than glycogen.
If you do expend a lot of energy then yes, you do need more carbs, but older people don’t expend that much energy even if they are somewhat active.
Yes, but that is part of the problem. The simple reality is that the human body has yet to evolve to plenty. It’s used to feast and famine. So it wants you to EAT and EAT and EAT. Especially fats and carbs, because they build fat. Which your body thinks it’s gonna need. So it releases endorphins when you eat them, rewards the brain, and makes you want more. We’re all drug addicts in the end. But you can still tell your body what fer. Enjoy the high and DON’T eat more. Keep your intake and output in balance, even as you get older. I’m actually about 20 pounds down from 5 years ago, adjusted to my new metabolism. Use the brain, don’t blame carbs or the government.