As noted, when I did the calculation, I worked out the extra calories consumed walking or biking compared to sitting down. So of course drivers eat. This analysis applies only if the walk/bike for transport was special exercise. For example, if you exercise every day, some days on a stationary bike and some days to get somewhere, you aren't changing your energy budget. If you decide to walk somewhere and otherwise you would not have done that exercise, then it takes extra energy.

However, again, this misses the point, which is not that we should sit down all day and not walk places. The point is we have created a system of agriculture where feeding ourselves consumes large amounts of oil, no matter what we do with the energy.