Most hotels I’ve been to have milk and oat meal too, basically what I’d get an average day. Nah I’ve been fine with hotel breakfast even travelling for work, pretty much the same shit I eat at home and then some occasional candy like food like waffles and pancakes.

Couldn’t really find any sources, but honestly it sounds reasonable enough. Engines are way more specialized for their single mechanical task than our legs are.

Of course you also move around way, way more weight most of the time. The mass/payload ratio is way worse with cars than with bikes so the comparable thermal efficiency would need to be greater to make up for that.

Beyond being a curiosity it is a moot point anyways. Humans need exercise to be healthy, and as you said, there are other environmental factors like car construction, gas refinement, etc. That I imagine mostly favour bikes too.