In spoken and sign language, words can be emphasized for meaning and intensity. We understand the differences between being cold and COLD or Freezing, and we know that exaggeration is not meant to be taken literally. There is a difference between a student in gym class who says he or she is dying of thirst and someone who has been in a desert for two days without water. In ASL, signs may be done more forcefully to emphasize meaning, with limits.
Sometimes, a sign done too emphatically takes on a new meaning. "Hungry" can mean simple hunger. If done repeatedly and dramatically, it can indicate lust. In the same way, "want" can range from a wish to a deeply physical desire.
In the story of Rachel's rivalry with her sister, Leah, in Genesis 30, Rachel is envious that Leah has borne four sons, while she remains barren. Jacob loves Rachel, but Leah is the wife who has produced offspring. In verses 14-16, Reuben, Leah's firstborn, finds mandrakes in the field and brings them home to his mother. Mandrakes were thought to increase fertility. You could say that Rachel is hungry for those mandrakes and wants them in every sense of the word. Although neither "hunger" nor "want" are directly used in the text, when Rachel says to Leah, "Please give me some of your son's mandrakes," using one or both of the signs could help bring that subtext to the forefront.
On the other hand, if you are telling Luke 15 (the Prodigal Son, or by whatever name you may know it), you might not want to say of the younger son, "Here I am dying of hunger!" with a lustful connotation, especially not while he is sitting among the pigs! An audience with any members who know sign language would receive a message you probably don't want to present. Sometimes hunger is just a physical state.