[ChuckMcM]

Perhaps its counter acted by them telling me all the time how much better it is than solid food :-).

But more seriously you do have a valid (if taken to an extreme) point. But similar arguments are made by people on segways losing walking endurance (or cars even). Actual atrophy seems to require complete non-use.

[jacobolus]

People using motor vehicles all the time absolutely causes atrophy. Lack of mobility among the sedentary (especially sedentary and obese) part of the population is a serious problem. There are a substantial number of people who have difficulty walking even a couple of blocks, not through any prior injury or disability, but just through disuse of their legs.

My wife and I were at the Biltmore estate in North Carolina a couple years ago. We wandered through the gardens, and we were chatting with a couple of ladies about what we had seen. They were shocked that we had walked a half mile from the parking lot instead of taking the shuttle. “You walked all the way from the house to here?!”