FODMAPs sounds like a bad RPG setting, but it's actually a crazy acronym for "fermentable – oligo- di- and monosaccharides and polyols". I have to give a shout-out to Kurt Harris for posting this, since it explains why I had some GERD type symptoms on Atkins.
These FODMAP foods ferment in your colon and can cause big problems. It's good to know if you're having digestive issues, since reducing these should be an easy tweak. Here's the list from Harris' article, paraphrased:
Diabetic sugar-alcohols, fructose rich foods and drinks, onions, jerusalem artichokes, wheat, tomatoes, apples, peaches, pears, apples, watermelon etc.
I was eating a ton of onions and sugar-alcohols on Atkins, and onions in particular seemed to give me fits. It never seemed like I was digesting them well. I thought that this was some personal digestive issue, since I limited intake of all of these with the exception of tomatoes and onions, this is no longer a big issue for me.
It's a good thing to keep in mind, folks!