Nuts are delicious and healthy and full of protein. They work wonderfully as  meat substitute in rice dishes, such as cashews in this stuffed pepper recipe, or added flavor in cooked vegetable salads, such as almonds in this zucchini salad.
All nuts are pretty much equal in terms of calories, but the lowest in calories (and thus the healthiest in the case of nuts) are almonds, cashews, and pistachios, and the highest in calories are pecans and macadamia nuts (though they are still healthy since they are, as all nuts are, filled with protein, good fats, and fiber). Also, my favorite “nut,” the peanut, is really good for your brain, so enjoy that natural peanut butter with no added sugar or salt (in moderation)!
However, nuts in general are pretty high in calories so they should all be eaten in moderation. Also, you should avoid roasted or salted nuts, since you do not know what kind of oil was used to roast the nuts or how much salt was added.
Furthermore, as far as nut flours are concerned, they double in nutrition if the shells are included in the flour.
Happy Eating,
Ashley