Drinking something really sugary, or even just bad for you can open up to some other unhealthy choices later on in the day.
I like to drink chocolate milk, for example, and I usually have at least a glass full.
I know it's bad or semi-bad, so before I drink a glass of chocolate milk, I fill the cup that I'm going to use full of water.
Drink the whole cup of water before filling it with chocolate milk or some other sugary drink, that is...
If you're still thirsty after drinking the water.
There are times when I won't drink the chocolate milk after the water because the water quenches my thirst, and I decide I don't want the milk anymore.
Hope this helps!