When I was a kid if you told Grandma you wanted "a little bit" of mashed potatoes at dinner you would get a normal sized serving. If you messed up and told her you were hungry she'd give you half the bowl and a giant slice of pie after.
I needed that as a teen. I went from 5' 5" (165cm) to 6' 2" (188cm) over the course of 3 years. If I was particularly hungry, I'd eat 2/3 of the bowl
Edit: I feel like it's necessary to mention that I wouldn't eat more than 2/3 of the bowl because I felt like it would be unfair to have more than that