This experiment might be good for people who can afford to do it, that is, people who do not know just how much they really spend on food. It might also be useful, as suggested upthread, to clarify the matter of portion control. However, I am skeptical about the premise, which seems to serve to manage the Whole Foods image as Whole Paycheck. That is not, however, my principal objection to the enterprise.
I am concerned that peppy conclusions of dubious validity will be drawn from this exercise, with a negative impact on those who can least afford to be subjected to them. It is one thing to try this experiment for a limited time and another to implement this budget on an ongoing basis. Why?
First, even looking at the meal as if it takes place in an isolated laboratory, economies of scale figure prominently in the cost of a meal for a few people. You will never convince me that a meal for three people costs 25% less than a meal for four, for instance.
Second, in these types of experiments, people don't realize how much they draw from the stores of staples and incidentals (salt and pepper, oil, flour etc.) they have on hand. (MHays' excellent Food Desert thread handles this problem carefully, and may be a good reference for this blogger, though the "healthy" focus is set aside.) Also the blogger has made a number of exceptions to the budget, such as coffee. Who will seriously argue that coffee is not an item that an American with average expectations would find in his or her household?
And, since I bring up the matter of average expectations, consider that Americans' average expectations for sustenance have risen over the years. As an example, I recall that Cathy2 encountered some disagreement over the menu and portions served at the Midwest Foodways Depression-Era dinner, which was based on a government menu for a family of the time. Apparently, some felt that it was inappropriate to subject symposium participants to such a meager offering, though the point of serving the menu was to acquaint the participants in a visceral way with the challenges of those hard times. The point is that people eat in a social context; their expectations are shaped by what goes on around them. Without choosing to entertain guests, there are more occasions than people acknowledge when one needs to participate in a bake sale, a pot luck, snacks for a kids' group, a work event event, etc. These are not things one can plan for in a tight budget. This situation is particularly hard on families that limit their expenditures out of necessity.
I suspect that in current conditions of comparative plenty for most, a family who participates in the Whole Foods $100 challenge will abandon it with alacrity.
Most importantly, in figuring the cost of a meal, the cost of time to prepare it, access to a store (see again the food desert thread) and the electricity and gas needed to cook it are not incidental. The assumption behind this Whole Foods-sponsored exercise may be that someone (likely the mother) has unlimited time and energy that she is not currently applying to feeding her family. Doesn't that leave out the person who is working two jobs to support a family? The person living far from a Whole Foods? What about the single parent, the disabled head of household, the person with limited extended family support?
My point is that in our society, there are too many people who are subjected to others' uniformed views about what is a "correct" amount to spend on food. I am familiar with a situation where a family court judge decided that $150/week was too much to spend on food for a working mother and two children with special dietary needs (food allergies). One wonders whether the judges are working with actual data.
I guess I think that this challenge is something one does if one can afford to, as a creative exercise. I'm all for a creative exercise, but this one lacks value as anything but a curiosity. IMO, Whole Foods is not all about healthy eating on a budget. Their offerings make it clear that they are a gourmet store with eco-friendly aspirations. A person shopping there on a restricted budget would likely get tired of being tantalized by expensive fresh breads and imported cheeses. A different challenge to target their typical customer would be based on health, sustainability, or happiness benchmarks.
Man : I can't understand how a poet like you can eat that stuff.
T. S. Eliot: Ah, but you're not a poet.