I really like "Eat Natural" muesli bars as snacks. They have no additives (though they have some sugar) and come in lots of yummy flavours, have loads of lumps of fruit and nuts in them, and some are chocolate or yoghurt coated. Most health food stores have them, and the larger supermarkets. I find a couple will keep me going if I don't have time to eat, so long as I've had a good breakfast in the morning. Though personally, I do keep going a lot better if I have some real food too - like wholemeal bread sandwiches or pitta bread with lots of nutritious filling.
