1. Edamame - Microwave a bowl of them in their pods about a minute and a half, stir them around, zap them another minute, and eat while taking a short break or thinking over some aspect of what you are working on.
2. Chocolate - Place a handful of cracked cacao beans in a small bowl and nibble on them during the course of the day. Cacao beans vary a lot in flavor and effect based on where they're grown and cultivation conditions, much like fine wine. Ecuador and Peru export good ones. The very best are from Guatemala but are hard to find.
3. Yogurt and Blueberries - Fill half a bowl with Greek yogurt and mix a handful of blueberries into it, fresh when in season. Frozen blueberries vary considerably in quality, so when you find good ones, keep them stocked in your freezer.
4. Almonds - Put about twenty in a small bowl and eat three or four at a time. The secret is to not have a big pile of them available at hand's reach, which leads (me) to eating them all, which doesn't produce the desired effect.
5. Onions, Black Beans and Rice - This one takes a little more work, but not much. Slice up a good yellow or sweet onion. Place the slices in a skillet (I prefer iron) with some sweet butter, and cook slowly over a low flame, occasionally mixing with a wooden spoon until the onion is lightly browned (about twenty-five to thirty minutes - you can smell when it is perfect). While it is cooking, make the rice and black beans. Black beans take a long time to prepare from scratch (overnight), so I nuke canned or boxed for a minute or two. Then place everything next to each other on a dinner plate. Great for when you need to power up while taking a short break.