You can do with your diet what you want. But for while you are actually on the bike, I wouldn't think consuming carb's will be any issue for ones long term health. It's not like you are completely replenishing with carbs the amount of carbs you burn. Because you can't.
So the bulk of what affects you long term is going to be what you eat off the bike, and if you aren't a pro trying to get back the 20,000 Calories you burned that day then most any diet you care to eat or believe is extra healthy for long term will provide for the measly 2000 maybe as much as 4000 or so Calories we lower life cyclist will burn. And we won't even burn that every day like the pro's will.