nuts get a bad rap in fitness by so many guru's.. i actually eat nuts daily and look at how lean I am.. you won't get fat off nuts unless you are eating them in addition to too much food. also nuts aren't the easiest thing to digest so you never want to eat them before a workout either.
here is the problem though with nuts and this is A BIG ONE to pay attention to. you better be reading the ingredients when you buy them. all the nuts you buy from your supermarket will contain added oils, salt, and preservatives. that isn't healthy at all
so when you get nuts you better get RAW and plain nuts. luckily i shop at whole foods and i can buy organic fresh nuts with zero added anything.. if you don't have access to a health food store that sells that then buy nuts online in the shell and have them shipped to you