High potassium foods/veggies/supplements seem to do the trick quite well. Try eating a banana. You'll also get the added benefit of vitamin B6, vitamin C and roughly 3g of dietary fiber. Raw spinach would also be a good choice - although I'm not too fond of that choice -.- Meal replacement supplements also provide large amounts of potassium. I personally use EAS Myoplexe Deluxe as part of my lunch - mixing it in a bottle provides a drink that (along with other brands of meal replacements of course) provides far more nutrition than non-MRP drinks. Also, there is more potassium as well as calcium and other vitamins in it than pretty much any meal you could make on your own. The price is fairly expensive, so you may wish to go with a cheaper brand. Another alternative is to go with a health drink. I personally like Vanilla Chai Tea by Bolthouse Farms. It's available at most grocery stores somewhere in the produce section. I used to get tired throughout the day, however now that I started adding more high-potassium, high B-vitamin foods into my diet, I'm rarely tired even on the odd day when I get only 5-6 hours of sleep.