It depends on how you do your accounting. The electric bike is more efficient than the pushbike, just as the pushbike + human is more efficient than the pushbik

It depends on how you do your accounting. The electric bike is more efficient than the pushbike, just as the pushbike + human is more efficient than the pushbike alone. The carbon cost of a joule of food is higher than a joule of electricity, and joules are what get you where you're going. You can make a case that it's nice exercise you needed anyway; I like bikes as well. But the claim you're making isn't obviously correct and I would say it's more false than true.