I keep about the same snacks as Leggott. You have to be a bit careful what yogurt you buy though. I find some here have up to 40gm carb per 100gm where others have 12gm carb per 100gm. Khaleb like Cruskits now also. They are really light and you can put any assortment of things on them. I make muffins that I grate carrot, zucchini or apple into. It doesn't affect the taste of muffins not to put as much sugar in as the recipes recommended. I also keep the little kids containers of fruit (diced or puree). Having a milk type drink like those breakfast milks are also a quick fix. They are called Up & Go here but could be completely different in the UK.