United Kingdom, July 16 -- Matt Damon returned to his high school weight to portray Odysseus in Christopher Nolan's The Odyssey.

The Oscar-winning actor, 55, stars as King Odysseus in Christopher's adaptation of Homer's ancient Greek epic, which follows the legendary warrior's 20-year journey home after the Trojan War, and Matt has now described the physically demanding production as the most challenging film of his career.

To prepare for the role, Matt reduced his weight to 167 lbs - his high school weight - while adopting a strict diet and undergoing an intensive fitness regime before filming across Iceland, Scotland, Greece, Italy and Morocco.

The Odyssey, which opens in cinemas on 17 July, also stars Anne Hathaway as Odysseus' wife...