It's sweet, slightly addictive and the bane of dentists everywhere. Still, the average kid drinks a couple of sodas every day, reports the Center for the Science in the Public Interest, making all that sugar a chief culprit behind obesity, diabetes and other health problems. Plus, letting your toddler or preschooler sip on soda can have lifelong consequences. A study published in the Journal of the American Dietetic Association found that girls who drank soda continued the habit as adults, opting for sodas over nutrient-rich drinks, such as milk. But don't assume diet soft drinks offer a loophole: A Purdue University study found drinking artificially sweetened sodas may cause weight gain, too.