Caine is pretty much dead on. I won't go into all of the nutritional benefits and pit-falls about nuts. But I will say this; All nuts are not created equal!.
Some of the little things we call nuts are seeds while some are actually fruits. The walnut and pecan, for instance, are in the same plant family as are peaches, and avacadoes. Tey all elong to the drupes (I think. Too little sleep has me a bit foggy today.). They are high in anti-0xidants, mono-unsaturate fats, vitamins, and minerals. With some of this family, you eat the skin and meat surounding the seed, while in others, you crack open the seed casing to get at the inside.
Sunflowers seeds, sesame seeds, and others like them have significant amounts of polyunsaturates and mono-unsaturants, as well as vitamins, minerals and fiber. But they aren't quite as healthy as are the walnuts and pecans.
Then there are peanuts, not a real nut at all. It's a member of the legume family along with peas, lentils, and beans. It too is a heathy food, but in moderation.
Cashew and Brazil nuts are truly deliscious due to their high fat and carbohydrate content. They give you a moderate amount of fiber, but should be eaten more sparingly than other nuts. They are very high calorie nuts.
Unfortunately, the same is true of macadamia nuts and hazlenuts (filberts).
So you have to do some research before you can really be informed about nuts, legumes, and nut oils. There is no simple answer to your question. On the plus side, you will become a nut expert (I didn't have to study the above mentioned plant foods to become a nut expert. I raised four kids to adulthood.
) The info you learn will be well worth the effort you expend. And it's interesting stuff.
Seeeeeeya; Goodweed of the North