>Thanks,any specific nuts? and any kind of fruit?
Good nuts are almonds (for calcium), walnuts (for omega fatty acids), brazil nuts (for selenium). IMO, it's best to get raw, organic nuts (not roasted and salted). If you like the crunchier texture of roasted nuts, soak raw nuts overnight (which actually makes them start to germinate, and their nutritional profile improves, just as sprouting improves the nutritional profile of grains, seeds and beans), then rinse and dry them. If you dry them in a dehydrator (under 115 degrees), they get nice and crunchy, and you can make flavored nuts by adding a bit of moisture (agave nectar, maple syrup, olive oil) a touch of salt, and spices (sweet spices like cinnamon with the sweet moisture sources, more tangy spices, like paprika, garlic powder, italian or mexican spices, etc. with the olive oil.
Don't go overboard, though, as nuts are very high in fat (good fat, but fat nonetheless--about 70% or more of their calories come from it). A handful or so a day is plenty.
For fruits, berries are excellent sources of antioxidants and phytonutrients, and are low glycemic. Apples and pears are high in pectin, a good fiber. Go easy on bananas, which are high glycemic fruits. They are best eaten in moderation, with some fat or protein (like a bit of banana in a protein smoothie: take ripe bananas, peel and break into chunks, and freeze. Drop 1 or two chunks in a smoothie for sweetness and to cool it down). Their high glycemic index does make them good to eat after a workout, when the body needs to replenish glycogen (the type of sugar the brain and body use) ASAP.
As for 'clean eating': generally, 'clean' food is food that you can understand all the ingredients in (they are things you can prepare yourself) and is minimally processed. Some ingredients---hydrogenated and partially hydrogenated oils, high fructose corn syrup/sweetener--are decidedly NOT clean. I'd put artificial sweeteners in general in that category, though others may not (though IMO, anything made chemically rather than 'grown' can't be that healthy for us).
I prefer the term "whole foods," which is more or less the same concept, but doesn't have the moral connotations of 'clean' eating.(and it's a concept that's been around much longer than 'clean eating' which seems to have come from the bodybuilding world.) It's also easier to understand, IMO. (brown rice, for example is a 'whole' food, but white rice isn't.)
HTH