With every new diet craze that sweeps our increasingly plump continent, a tremendous transformation takes place. Alas, not in the pudgy body shapes that struggle towards trimness. But on the grocery shelves of our local supermarkets.

Have you noticed the transformation? (At this point you may want to hold up some of these items you're talking about.) Our foodstuffs are changed from their most basic forms so that they fit whatever diet regimen reigns supreme.

First, it was banning sugar. Suddenly sugar-free, artificially sweetened sodas, cookies, and chocolates filled the grocery shelves.

Then fats became public enemy number one. Suddenly fat-free chips, ice cream, and butter-substitutes made greasy fingers obsolete. Dr. Dean Ornish made the low-fat diet popular, even among the presidents. …