I think only sweet potatoes are. Not sure though so hopefully someone else will chime in. I don't really care about potatoes so I haven't bothered to find out. But I do know you can make mashed "potatoes" with califlower.

I've read that white potatoes can be problematic for peopel with autoimmune disorders (along with a few other veg) For anyone else stay away if you are trying to lose weight. I still eat them occasionally but choose sweet when I can.

Sweet potatoes are great

I don't blame you for being confused, I've read so many conflicting websites that list what is ok and what is not. On some, sweet potatoes are definitely out, as is bacon (which we've already determined we're not giving up). I personally love sweet potatoes and would hate to lose them since they can be fast, easy, as well as delicious and filling. White potatoes seem to be out no matter what site I look at though. Now how about mayonnaise? Is that ok to eat? And canola oil? What the heck is it made out of anyway?

Here's another article

http://www.naturalnews.com/027978_nightshade_vegetables.html

Oh yes, and the nightshade thing

it often depends on the individual. Some people can tolerate foods others can't. Anyway, perhaps try eliminating potatoes for 30 days and see how you feel. Then add them back in and see how you feel.

From a sheer nutrient standpoint white potatoes are pretty much dunces and even worse if you have a preexisting autoimmune disorder ( as it is a nightshade). Sweet potatoes, if you are into starches, are fantastic and more delicious IMO with higher nutrient density. As someone else mentioned, the fructose in sweet potatoes can bother some and impede fat loss in many.

Someone had inquired about mayo a few posts up- ideally, make your own mayo using light olive oil, coconut oil, red palm oil, or even bacon drippings if you have some handy. If you are strapped and/or uneasy about using a food processor for mayo then go for one with expeller-pressed canola oil and cafe-free eggs such as Spectrum.

As others have mentioned, the problem with potatoes are that they provide starch (carbs) and not much else, and eating primal/paleo is all about the insulin. While other roots like sweet potatoes get a more favored response, it's because they provide a good nutritional input despite the carbs. Personally, I avoid sweet potatoes as well, except thanksgiving (when family's here) because it provides a healthier alternative to mashed potatoes.

My personal mantra is: Whole foods, organically grown - and simply prepared.

Going along with that, one can basically figure out how paleo a food is by how edible it is raw. We were hunter/gatherers way before we discovered how to cook, and for the longest time cooking was simply searing flesh or putting plants in the hot coals. Nearly all complicated processes to make something edible developed after agriculture was discovered. When looked at in this light, a yam cooked on coals would be edible - but I daresay the potato isn't unless you slather it with butter, sour cream and chives.

Now, obviously everything that winds up in a salad can be eaten raw - but what about other foods? In the root area, carrots, radishes, beets, turnips can all be eaten raw - but I don't see anyone eating yams or potatoes raw. While that shouldn't be an automatic disqualifier, when you consider that grains and legumes cannot be eaten unless they are leeched, processed and cooked - it should make you look twice (and eat less, in my opinion).