Question about a child

L. is 5 years old. She has three large meals and two snacks in between: one after her first meal and one after her second meal. However, she is always hungry. She is constantly asking for another snack. When she eats, she eats fast. She stuffs her mouth with food and literary swallows it without chewing. She used to receive additional snacks when she was asking, but now, because she has gained a lot of weight and is overweight, she is being told, “No.” But even though she knows that she will be told, “No,” she still keeps begging and whining and gets very upset when she does not get food.

How often is it ok for a child of her age to eat? And how much food is ok? Please guide us.

Thank you.