Everybody knows a few aggressively healthy eaters. These are the people who condescendingly nibble tofu while everybody else is indulging in a Twinkie binge, the people who demand at dinner to know the provenance of the chicken, the people who read every label on every supermarket packet, searching for the organic, the sugar-free, the gluten-free, the low-fat, the low-salt, and the local.

Don’t get me wrong: I’m all in favor of healthy eating. It’s admirable, desirable, and all of us should do more of it. But, as it turns out, too much of a good thing isn’t necessarily wonderful.

A new eating disorder is popping up in the news lately that describes people who take eating healthfully to an extreme. But the