The once pizza-loving Serb revealed his journey from an allergy-ridden, chronically fatigued sportsman - who often collapsed on the court - to someone who rises at dawn each day with more than a spring in his step.
We take a look at his book: Serve To Win and see what lessons can be learnt for those of us who suspect (or believe) we are sensitive to gluten and that this protein in wheat is to blame for a host of health problems, from bloating and mind fog to breathing problems and aching joints.
Read up: How Novak Djokovic went gluten-free.