Which is more healthy? A meal with meat and potatoes(not yams/sweet potatoes because we don't have these kind here), or one with meat and white rice? I know that potatoes and rice aren't really healthy but which one does less harm, based on the evidence so far?
Potatoes have more nutrients. Rice is basically just empty calories. It probably doesn't matter much if you just eat a bit now and again. If you have poor blood sugar control or are trying to lose weight, then avoid them both. If you are eating a lot of it, I'd say potatoes would be much better than rice because potatoes contribute more nutrition.
Interesting question, but as a practical matter I think you are slicing the salami pretty thin.
What I mean is that if your diet is so good that you are worried about this... don't worry about it!
If you have already dumped sugar, grains, and industrial oils, and are eating grass-fed/pastured meat, the difference between white potatoes and white rice is negligible.
I'd go for the potatoes as they're more filling than rice (and lower carb density, 16% vs 28%), plus you can do more interesting things with them -- like pressed potatoes (= "rice"), mashed potatoes, fried potatoes or what have you.
Had it been about rice in general vs potatoes, I'd also go with the potatoes as it contains less anti-nutrients. Except for green potatoes, watch out for those!
If, however, you're merely looking for a side dish, have a look at the thread on a side dish: http://paleohacks.com/questions/1575/what-do-you-use-to-substitute-potatoes-as-the-side-dish/1591#1591
Personally, I've recently upped the amount of fat quite a bit, so the dish itself tends to be filling, e.g. a spinach soup/stew based on coconut butter or full cream, cheese-filled beef, and so on. It's a very different feeling compared to the "stomach full" signal you get from eating carbs. And it's so much better...
Nutrient wise, a sweet potatoe seems like a clear winner over white rice. white rice. And these foods can have nutrients that are somewhat difficult to get in meat, for example potatoes have a large amount of vitamin C.
Nutirion Data also has an inflammation index, where sweet potatoe scores 505 (that is good) and white rice scores -176. I don't know if that index is actually valid information or not.
As far as I know (which is not much), white rice is mostly free of anti-nutrients. Potatoes have alkaloids, but they are mostly in the skin, see Stephen's comments on Don's Primal Potatoes post.
I have serious issues digesting grains, and rice both tears up my stomach and binds me up. (Ew.) I'd choose the potato. Plus, I actually /like/ the taste of potatoes, versus rice, which is appallingly bland to me. :)
Potato skins have most of the glykoalkaloid content that could contribute to health problems of intestinal nature.
Personally, it depends on you. What I recommend you do is test your blood glucose both before and after eating each of them separately.
The white inside of a potato will contribute to a net renal basal load, helping to prevent low grade metabolic acidosis which most people on SAD suffer from.
I eat a lot of white rice, but I'm in Asia. It's not so bad but it's not good either (no micronutrients). I eat it for the carb content and calories because I'm a training athlete. As an athlete I have no insulin sensitivity or diabetes problems. If you're in a similar situation then I wouldn't be scared of the GI of these two foods, especially pre and post workout.
Since sweet potatoes and yams are basically the same price as regular potatoes where I live, I eat those. No point playing around with potatoes when sweet potato is the same price. If you read a lot of the Paleo blogs out there, you'll know that we have evidence of healthy cultures eating tubers like sweet potato and yam for a high percentage of their calories (Kitava, Tokalau). So if I were to steer you into the direction of a cheap starchy carb it would be those.
I no longer eat them, but if I was forced to choose between the two, I'd choose any (preferably organic) tuber over any grain for a number of reasons. Here's a couple of non-scientific reasons: many brands of rice might be cross-contaminated by gluten grains during the packaging process, and I happen to like the taste of potatoes better than rice.