French chef Paul Bocuse, dubbed the "pope" of cuisine, has been hospitalized for nearly a week with back pain.
Bocuse, who will turn 88 in February, has been suffering from violent back pain for more than three months, which had forced him onto crutches, an aide has told AFP.
Since Monday, he has been under observation at a hospital in the southeastern city of Lyon, though his condition is not said to be serious.
"He must undergo some more tests and extend his treatment," another aide told AFP.
Bocuse suffers from Parkinson's disease, has had several coronary bypasses and has had an artificial heart valve for eight years.
Bocuse is a giant of 20th century world cuisine and a trend-setting globe-trotter for the culinary arts.
He helped shake up the food world in the 1970s with the Nouvelle Cuisine revolution and gave a boost to the profession of chef in the process.
A patriarch among his peers in a nation that prides itself as the beating heart of gastronomy, Bocuse was France's only chef to succeed in keeping the Michelin food bible's coveted three-star rating through more than four decades.
Coming from a profession known for outsized egos and explosive tempers, he is well-loved for his charisma, showmanship and good humour.
Known to staff as "Monsieur Paul", he was named "chef of the century" by Michelin's rival guide, the Gault-Millau, and in 2007 more than 80 top chefs flew in from around the world to celebrate his 81st birthday.