Keep kids' caffeine consumption in check

Most parents wouldn't dream of giving their kids a mug of coffee, but might routinely serve soft drinks containing caffeine.

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 can of soda or four 1.5-ounce milk-chocolate bars.

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.

Besides that it can cause jitteriness, headaches and difficulty concentrating and sleeping, reasons to limit kids' caffeine consumption include:

Kids who consume one or more 12-ounce sweetened soft drink per day are 60 percent more likely to be obese.

Kids who fill up on caffeinated beverages 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 from the high sugar content and the erosion of tooth enamel from acidity. One 12-ounce non-diet, carbonated soft drink contains the equivalent of 10 teaspoons of sugar 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 cause dehydration is not clear, however.