Always read the labels! Always!
I recently purchased a bottle of coconut water for making coconut water kefer. Unfortunately I did not read the label, which is unusual. I read ALL labels! A couple of days later a food blog I follow on Instagram posted a picture of the label from the brand of coconut water I had purchased! I was shocked to discover what the ingredients were. "But it's coconut water" I had thought at the time. What could they possibly change? Of course I should have checked for added sugar, etc... and now I know better.
Lesson learned! You never know what kind of sneaky ingredients are hiding unless you check.
In general, I try not to purchase packaged "food" because usually, it's not real food. In some instances, such as coconut water, I do make the choice to purchase packaged, because it's easier :D
So just because it has a pretty label (wins me over every time) and has all the nice wording on the front, it is still always best to read the label.