What's the Name of That Book??? discussion

I read this YA SciFi story in the early 80s. It takes place in the future. Some people occasionally reject civilization and run off to unoccupied planets to form primitive colonies in the wilderness. For some reason, this is illegal, so those that try are taking a big risk. The main character is a teenage girl named Romula (Rom for short). Her parents ran away from civilization and left her behind when she was just an infant, so she has issues. She and her classmates go on some sort of field trip to an uncolonized planet, but it turns out that their teacher is using this as an opportunity to defect to a secret nature colony he knows about. And he wants to take the kids with him, so they can't go back and report the location of the colony. Eventually they escape. One of the kids who was initially supportive of the idea changed his mind when he observed that the colonists had degenerated into people who no longer used their minds very much. Romula comes to forgive her parents when she realizes that they had actually done her a favor by not forcing the choice upon her when she was just a baby. I also recall that there were candy bars that the kids loved with a passion and that all kids ate. When the candy bars ran out, the kids realized that their purpose was to delay the onset of puberty. When they went back home, they stayed away from the candy bars.

But We Are Not of Earth by Jean E. Karl, 1981.

Summary:
Four students from Meniscus F on a mission to the far-away Sector 22 delight in the habitable but uninhabited planet they discover until they realize their pod mentor has no intention of allowing them to leave.

Wow! That must be it. I wish I could find a more complete synopsis that the Amazon reviews, but everything seems to match, including a character named Rom. Thank you, April!