He does mention in another post: "To be clear, I don’t mean to trivialize anyone else’s experience or claim mine as an authentic representation of what food insecurity looks like."

I'm pretty sure he's well aware of all the luxuries he has at his disposal that others who rely on food stamps don't. He's not shooting for an authentic representation because he just can't. Even if he were to give away all of his wealth, he'd still have many luxuries (such as friends and family to look after him) that some folks in dire situations don't.

This isn't to say that there isn't insight to be gained from running this experiment, though.

Well, the supermarket he is shopping at is located in Dorchester, which has some of the poorest neighborhoods in Boston.

False. 70% of the poor own a car and 25% own two cars.

http://www.census.gov/prod/2008pubs/h150-07.pdf