Problem: How does the sentence end?

As he walked through the open door, he immediately saw the cake on the counter but not the puddle on the floor, because the 
Answer: cake was obvious.

Problem: How does the sentence end?

Tanya helped Mary cook dinner, because 
Answer: Tanya has been a fantastic cook for while now.

Problem: How does the sentence end?

William had to add baking soda to their pool so they asked Aaron for help because 
Answer: Aaron had definitely cleaned their pool before.

Problem: How does the sentence end?

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