I decided to experiment a little during the last few weeks to see what kind of nuts are best for a paleo diet. I don't always include them, but often enough that it's worth figuring out which ones to use.
I stayed away from cashews, pecans, walnuts, pine nuts, and pistachios because of too much polyunsaturated fat or too much digestible carbs. Same for Brazil nuts, but these also taste terrible and have an unpleasant texture. Macadamia nuts are OK -- not carb-filled at all, and a decent amount of saturated fat -- but they're a bit too chalky and thus require a lot more chewing and grinding to process. Soynuts were out of the question since they're soy, one of the most poisonous substances you could eat (unless you ferment it like natto).
Since it was cheap to experiment with, I picked up some peanut butter (peanuts only), and raw almonds that were on sale. I won't be incorporating these because they're too easy to eat a lot of. Peanuts are not nuts but legumes, making peanut butter more like hummus, and human beings aren't adapted to a bean-heavy diet -- that's why we have to rely on our gut flora to digest that junk for us, yet we pay the price by getting gas. Almonds are a lot better as far as nutritional value, flavor, and texture go, but again it's too easy to go through half a pound in one sitting (not that I did this every time I ate them, but it did happen once).
Foods that we're adapted to fill us up and tell us to stop before long. The reason is that a meal is not fuel but an information signal. Food doesn't become usable fuel until hours or days later, bearing in mind that we had no access to pounds of sugar before 100 years ago or so, and except for some South Seas people with abundant coconuts, we had no access to lots of short-chain fatty acids that can be burned right away. Rather, a meal is a signal to our body that we can stop being so physically active -- we've accomplished our goal of finding and preparing food. If a meal were fuel, then when we ate a large meal our impulse would be to be very active, whereas in reality it is to kick back and be lazy for awhile.
So, any food that you "just can't stop" eating is not something we're meant to eat. Sugars and starches are the clearest example, but even almonds and cashews have enough of this to keep you snacking on and on. There is no natural negative feedback loop that says, "Woah, we get the message loud and clear -- you've found food -- so you can stop chowing down now." I went through what I planned as a week's small jar of peanut butter in several days, and one week I went through the first pound of almonds in just a few days and bought another one!
Aside from the obvious side effects of peanut butter making my belly inflate like a balloon, it also dried out my skin all over. Not as in flaking or peeling or getting ashy, but just a general feeling of dryness that I never have ordinarily. That happened when I tried corn tortillas awhile back, and when I bought a container of hummus as a vegetable dip. Beans and grains must interfere with the pathway whereby vitamin A maintains healthy skin (I eat a slice of liver cheese every morning, but that was to little avail in the presence of legumes). My face also broke out a bit, again not too surprising given how close to the low-carb border you can push it when eating a fair amount of almonds and peanut butter.
So this week it's back to my old favorite -- hazelnuts. They're true nuts, which humans are more adapted to, and we have archaeological evidence that pre-sedentary-farmer groups were eating them in Scotland. Like macadamias, they're very low-carb and like almonds they're high in monounsaturated fat (oleic acid, the stuff that olive oil is made of). They hardly taste sweet or starchy, and therefore my natural negative feedback loop kicks in after just a handful. At most I can eat 20 per sitting, which is about 1 oz., and sometimes just 10 is more than enough. Plus the texture feels just right -- crunchy but not chalky, and with enough flesh on the outside.
If you want an even more savory taste, crack them in half with your teeth, drizzle with olive oil, and sprinkle with sea salt and pepper. If you want the tiniest hint of sweetness plus a load of ready-to-burn fat, have a little bit of coconut chips with them. Best of all, they're hardly more expensive than almonds, and because you can't eat as much of them, they cost more or less the same over a week. I'd advise against hazelnut butter (made by Kettle), as it's way too savory to replace the nuts themselves, and the smooth texture isn't as satisfying as crunching the real thing between your molars.