My eating logs show a dramatic calorie increase when cycling to work vs not. Eye balling looks like ~20% increases are common

When I cycled to work I did eat more, but that was 30+ miles a day up and down hills. It was also on an ebike (whatever that proves) and I would say it was more carbs than air freighted fresh veg and meat, so not the most carbon intensive food.

But yes I don't think most people eat their full extra cycling energy expenditure when they take up cycling.