In the What's Eating Gilbert Grape the family members are eating Gilbert but everyone at a different rate. Gilbert is affected by everyone in his family even the members who have died or run away. Gilbert is affected also the responsibility that he has to take because so of those people are not there to help them or are there but instead of helping him they are putting more weight on his shoulders. Gilbert has the least responsibility to the most from Ellen, Arnie, Amy, Larry, Momma, and Albert.
Ellen is the person who eats Gilbert the least. Since she is the one who basically understands that there should be responsibility and that Arnie isn't responsible for most of his actions. She wants the family to see life as what it is not to pretend that everything in life is perfect. She knows that everyone in the family seems not to notice how Momma is and she is the only one that tells everyone that Arnie is up the tree.
Arnie might be a weight for Gilbert at times but he is the only reason that Gilbert hasn't left the family. Probably because there would be no man left in the house to take care of the family since Momma is no help to the family instead she is a weight into the family. Arnie also is like Gilbert's true friend until Becky appears in Gilbert's life.
Amy seems to eat more Gilbert than we think she does. She is the one who feeds Momma and is like the housekeeper of the house. She in some way is responsible for what Momma has become a person who is dependent on most of his children. Amy has some fault since she doesn't make Momma do her own chores and she is basically taking care of the whole house.
Larry the brother who runs away is also responsible for what has happened. He was the first son so he knew or should have been taught how to take care of his family in case his father died. He wasn't brave enough and didn't want to take care of his family. Larry left the chore to his brother...