While finding local meat is easy, the Northeast is lousy for growing popular items like rice, oranges and coffee beans. Finding local flour can be a challenge too.
The 100-milers try to make up for the lack of dietary variety with elan.
On a recent day, Rensselaer Polytechnic Institute student Ella Braco ate a breakfast of eggs with tomato, basil and mozzarella cheese. For lunch she had a monster salad with carrots, apple chunks, basil and parsley. Dinner was tomato soup.
''The hardest thing is giving up the free food on campus,'' Braco said. ''I've already missed three barbecues and a dinner date and a lunch date.''
Nechamen said it's typical for participants to do a lot of whining in the first week about all the food they're missing, but ''by the end of it, you're thinking of the things you've discovered.''
Nechamen learned to make biscuits. Shave has honed his skills as a local meat maven.
A frequently cited 2003 study found conventional produce traveled an average of almost 1,500 miles from farm to markets in Chicago and St. Louis. The study's author, Rich Pirog of the Leopold Center for Sustainable Agriculture, said distances could be even greater on the East Coast, given that so much produce comes from California.
But Pirog cautions consumers not to focus exclusively on so-called food miles. For instance, grapes shipped from Chile to Philadelphia might require less energy to transport than California grapes carried cross country by truck.
''Food miles have some limitations,'' Pirog said ''They are not the best indicator of either total energy used in transport or of greenhouse gases.''
Then there's a more personal problem with following the 100-mile rule: it's really hard. Participants routinely make exceptions so they can enjoy a cup of coffee or serve orange juice to their kids.
Nechamen, for instance, waives the 100-mile rule if she's making food from scratch. That allows her to put rolled oats in her granola. And she didn't fret about jazzing up her local-sourced chicken tortillas with some non-local lime juice.
''We try not to be obnoxious about it,'' she said. ''We try to be fun.''