The Englishman was chosen as one of three wildcard picks by Europe captain Paul McGinley for the biennial contest that begins at Gleneagles on September 26.
Westwood, who reached world number one in the official golf world rankings in 2010, has now revealed that he has shed 23 pounds over the past months in preparation for the event.
"What have I been doing at home? I've been vanishing," Westwood said.
"I've lost 23 pounds, doing double gym sessions - cardio in the morning and weights in the afternoon.
"I've been off the alcohol and been watching my diet."
The 41-year-old is preparing for the Ryder Cup by contesting the Wales Open this weekend, which is being held at Celtic Manor - the setting for Europe's last triumph on European soil in 2010.