CBS News/ June 29, 2012, 11:27 AM

Why am I so awake? 12 surprising sources of caffeine

The caffeine crutch

istockPhoto

Overworked and sleep-deprived? You're not the only one. Experts say more people are using caffeine as an energy crutch than ever before.

That's not all bad: In fact, 250 milligrams of caffeine per day - that's two to three cups of joe - wakes up the brain, improves concentration, relieves stress, and may also help you live longer. A recent study even found drinking two cups of coffee daily might reduce heart failure risk.

But if intake is turning into addiction, you may notice side effects, including dehydration, trouble sleeping, anxiety, upset stomach, and problems that may occur in pregnant women.

If you're trying to cut back on caffeine, you've probably already reduced the amount of coffee, tea, and sodas that you consume. But the sneaky stimulant can pop up in unexpected places. Since the U.S. Food and Drug Administration (FDA) doesn't require manufacturers to list caffeine content on nutrition labels, it's often hard to tell whether a product contains the stimulant, and how much. From our friends at Health.com, here are 12 sources of caffeine - some hidden, some just plain weird - that might be giving you the jitters.