It's no big secret – we're fatter and more prone to illness than ever before. And if you think adults are in bad shape, take a look at our kids.

It doesn't bode well for the future.

And the biggest problem with our kids' diets is not necessarily what they're eating – it's what they're drinking.

New research finds that replacing soda and sugary drinks with cool, refreshing water can help significantly reduce the number of calories kids consume each day.

The study in the Archives of Pediatrics and Adolescent Medicine found that when kids cut out the sugary drinks, they don't replace those calories with extra food or snacks.

When you consider that sugary drinks make up 10 percent to 15 percent of a typical child's daily caloric intake, that's nothing to sneeze at.

In fact, the researchers found that replacing all of a child's sugary drinks with H2O would cut about 235 calories from their diet each day.

Now, I know that raising kids ain't exactly like raising cattle. You put out feed and water for animals, and they'll pretty much eat and drink what you give them.

Kids have their own ideas about food, and they're usually bad ones. I've had to fight those same battles with my own sons, so I know how hard it can be.

But the numbers don't lie – give in to them now, and you can pretty much write their future health story for them, and it goes far beyond the obvious obesity problems.

Soda has been strongly linked to tooth decay, and some of its common ingredients have been tied to cell damage, liver disorders, and degenerative diseases.

These drinks have also been shown to cause lower calcium levels and higher phosphate levels in the bloodstream. As you age, that leads to bone loss and osteoporosis. For younger folks who drink a lot of soda, that could mean poor mineralization in the bones – and an increased risk of breaking those bones as a result.

And we haven't even touched on the problems caused by drinking caffeine from an early age.

So turn your home into a soda-free zone (and that goes for diet soda, too). Just keep some water in the fridge, and you'll always have a cool drink ready to quench any thirst.

Most importantly, talk to your kids about why you're doing it.

Chances are, your kids won't be impressed by your reasoning. They all think they're pretty much invincible anyway, mine included. But think of it as a basic health issue on par with teaching them about substance abuse.

Yes, it's that important.