Most parents wouldn't dream of giving their kids a mug of coffee, but might routinely serve soft drinks containing caffeine. Foods and drinks with caffeine are everywhere, but it's wise to keep caffeine consumption to a minimum, especially in younger kids.

The United States hasn't developed guidelines for caffeine intake and kids, but Canadian guidelines recommend that preschoolers get no more than 45 milligrams of caffeine a day. That's equivalent to the average amount of caffeine found in a 12-ounce (355-milliliter) can of soda or four 1.5-ounce (43-gram) milk chocolate bars.

How Caffeine Affects Kids

A stimulant that affects kids and adults similarly, caffeine is a drug that's naturally produced in the leaves and seeds of many plants. Caffeine is also made artificially and added to certain foods. Caffeine is defined as a drug because it stimulates the central nervous system. At lower levels, it can make people feel more alert and energetic.

In both kids and adults, too much caffeine can cause:

• jitteriness and nervousness
• upset stomach
• headaches
• difficulty concentrating
• difficulty sleeping
• increased heart rate
• increased blood pressure

Especially in young kids, it doesn't take a lot of caffeine to produce these effects.

Other reasons to limit kids' caffeine consumption include:

• Kids who consume one or more 12-ounce (355-milliliter) sweetened soft drink per day are 60% more likely to be obese.
• Not only do caffeinated beverages contain empty calories (calories that don't provide any nutrients), but kids who fill up on them don't get the vitamins and minerals they need from healthy sources, putting them at risk for nutritional deficiencies. In particular, kids who drink too much soda (which usually starts between the third and eighth grades) may miss getting the calcium they need from milk to build strong bones and teeth.
• Drinking too many sweetened caffeinated drinks could lead to dental cavities (or caries) from the high sugar content and the erosion of tooth enamel from acidity. Not convinced that sodas can wreak that much havoc on kids' teeth? Consider this: One 12-ounce (355-milliliter) nondiet, carbonated soft drink contains the equivalent of 10 teaspoons of sugar (49 milliliters) and 150 calories.
• Caffeine is a diuretic that causes the body to eliminate water (through urinating), which may contribute to dehydration. Whether the amount of caffeine in beverages is enough to actually cause dehydration is not clear, however. It may depend on whether the person drinking the beverage is used to caffeine and how much caffeine was consumed that day. To be on the safe side, it's wise to avoid excessive caffeine consumption in hot weather, when kids need to replace water lost through perspiration.
• Abruptly stopping caffeine may cause withdrawal symptoms (headaches, muscle aches, temporary depression, and irritability), especially for those who are used to consuming a lot.
• Caffeine can aggravate heart problems or nervous disorders, and some kids may not be aware that they're at risk.

One thing that caffeine doesn't do is stunt growth. Although scientists once worried that caffeine could hinder growth, this isn't supported by research.

Foods and Beverages With Caffeine

Although kids get most of their caffeine from sodas, it's also found in coffee, tea, chocolate, coffee ice cream or frozen yogurt, as well as pain relievers and other over-the-counter medicines. Some parents may give their kids iced tea in place of soda, thinking that it's a better alternative. But iced tea can contain as much sugar and caffeine as soda.

Here's how some sources of caffeine compare:

Sources: U.S. Food and Drug Administration and the National Soft Drink Association

What's Caffeine Sensitivity?

Caffeine sensitivity refers to the amount of caffeine that will produce an effect in someone, which varies from person to person. On average, the smaller the person, the less caffeine necessary to produce side effects. However, caffeine sensitivity is most affected by daily caffeine intake.

People who regularly drink beverages containing caffeine soon develop a reduced sensitivity to caffeine. This means they require higher doses of caffeine to achieve the same effects as someone who doesn't drink caffeinated drinks often. So, the more caffeine kids take in, the more caffeine they'll need to feel the same effects.

In addition to being more susceptible to the effects of caffeine based on size, younger kids are more sensitive because they haven't been exposed to it as much as older kids or adults.

Caffeine moves through the body within a few hours and is then passed through the urine. It's not stored in the body, but kids may feel its effects for up to 6 hours if they're sensitive to it.

Cutting Caffeine

Can you keep kids caffeine-free? Absolutely! The best way to cut caffeine (and added sugar) is to eliminate soda. Instead, offer water, milk, flavored seltzer, and 100% fruit juice. For added convenience, serve water in squeeze bottles that kids can carry around. You can still serve the occasional soda or tea — just make it noncaffeinated. And watch for hidden caffeine by checking the ingredient list on foods and beverages.

If your teen has taken up coffee drinking, one cup a day can easily turn into several (as most adults know), especially if your teen drinks it to stay awake during late-night study sessions.

The best way to reduce coffee caffeine intake is to cut back slowly. Otherwise, kids (and adults) could get headaches and feel achy, depressed, or just downright lousy.

Try substituting noncaffeinated drinks for caffeinated sodas and coffee (water, caffeine-free sodas, and caffeine-free teas). Keep track of how many caffeinated drinks your child has each day, and substitute one drink per week with a caffeine-free alternative until he or she has gotten below the 100-milligram mark.

Someone cutting back on caffeine may feel tired. The best bet is to hit the sack, not the sodas: It's just a body's way of saying that more rest is necessary. Don't worry — energy levels will return to normal in a few days.

Feel free to let kids indulge in a sliver of chocolate cake at birthday parties or a cup of tasty hot cocoa on a cold day — these choices don't pack enough caffeine punch to be harmful. As with everything, moderation is the key to keeping your kids' caffeine consumption under control.

Reviewed by: Mary L. Gavin, MD
Date reviewed: February 2012