Parents: If I have children of my own and they ask me to be honest even if it hurts, should I be brutally honest with them?

My mom was a brutally honest women and will tell you the truth, even it it's painful. My dad is too. My brothers and I are brutally honest with each other. I guess we got it from them.
Anyways when I kid gets older like elementary school and middle school, should I be brutally honest with them? I don't wanna sugarcoat life and the hardships of things. I don't want them bitching at me for not telling them the truth.