Drinking while on meal or after? Which is good for health?

When i was young my mom advised me to drink water before i start eating, actually i really don't know her reason. But as far as i know, she said that it can help in my diet, it can also make you lose weight in a healthy, but i am not sure about it since i don't usually follow it. I usually drink only after i finish meal.
I have observed it from my eating that i really need to eat more since i am skinny and thin. Everytime i drink water while eating i usually lost my appetite and be full easily. So to make me eat more i will only drink water only after meal.

I always have something to drink when I eat.

I've heard that if you'r trying to lose weight it helps to drink a glass of water before a meal too.

moonbutters