Ever wonder how science-fiction heroes, busy hurtling through space or battling evil robots, find the time to eat nutritious meals so they can keep going? The classic science-fiction solution is that in the future they’ll take in a day’s nourishment by popping a pill crammed with the RDAs (recommended dietary allowances) for all the food groups, along with a pleasing taste and a satisfying sense of fullness. One little tablet and your favorite hero is good for another 24 hours of action.