Problem: How does the sentence end?

Cynthia's hair was more silky than Emily's because
Answer: Emily spent little time on her hair care routine.

Problem: How does the sentence end?

Monica asked Amy to help her get a volunteer position at the animal shelter as
Answer: Amy has long been involved with animal rights.

Problem: How does the sentence end?

The muscle on the arm hurt more than the muscle on the leg because the
Answer: leg had been warmed up.

Problem: How does the sentence end?

So
Answer:
Patricia wanted to change their diet because Patricia wanted to lose weight while Samantha was fine.