Yes. In my neighborhood, there are several produce-only stores, so I never really thought much about it. But imagine a place where over 70% of the people who live there are fat. Keep in mind that the remaining 30% not necessarily are healthy or fit, they just have enough self-control not to balloon themselves to planetary size. Who's going to buy produce? Now, imagine a world where entire countries have crossed that threshold already. You don't need to imagine, this is the Earth you're living in.