The 23-year-old proved his Premier League pedigree on loan at Crystal Palace last season.
And he has continued that form at Chelsea, having scored 9 goals and provided 5 assists in 39 appearances.
"This is the best spell of my Chelsea career in terms of games and goals," said Loftus-Cheek.
"It is due to playing more and being largely injury-free. It's time to stop being seen as a young player and earn my rewards on merit.
"I've learned how to manage my ongoing back issues and have been free from problems for weeks.
"Playing every three days means I need to rest properly and work with the medical staff but they are finding solutions."