[OkayPhysicist]

A human walking is absurdly efficient, as anyone who's ever tried to outrun a bad diet can tell you. Running or walking a mile burns ~100 extra calories relative to sitting on your couch. Unless you're putting active effort into not doing so, most diets fluctuate by far more than that.

[hollerith]

Sure, but it is also true that food that is healthy for people is an absurdly expensive form of energy compared to gasoline.

[wolverine876]

If we make free the largest costs of gas, greenhouse gas emissions.

[hollerith]

Even if we count the cost of the co2 emissions: it probably takes more petroleum products to grow the food for the walking delivery workers than it takes to fuel the delivery truck.