>A vehicle full of groceries means you don't have fresh groceries for most of the time.

Luckily we invented refrigerators so this is not an issue. Things can stay fresh and just as healthy for weeks.

>More resources? If you're walking to the store, this shouldn't be an issue, and in fact is a negative. Avoiding walking is why Americans are so fat.

As in, buying in bulk saves money and resources versus buying in small amounts. Indeed Americans are fat, but adding a few walks here and there isn't going to fix that. American diet is absolute garbage and the portions are insane.