In this photo released by Harpo Productions Inc., talk-show host Oprah Winfrey, right, stands with actress Drew Barrymore during the 'The Oprah Winfrey Show' which aired Monday, March 3, 2008, in Chicago. [Agencies]

Drew Barrymore said Monday she is donating $1 million to help fight hunger.

She made the announcement on "The Oprah Winfrey Show," saying she would give the money to the World Food Program, a U.N. body that delivers millions of tons of food aid to more than 70 million people in about 80 countries.

"I'm able to make this incredible donation — this has changed my life," she said on the program. "But I encourage everyone to give."

Barrymore, who serves as a World Food Program ambassador, later told The Associated Press that the $1 million is the largest donation she's made.

"By far," the 33-year-old actress said. "But nothing has ever felt so good."

Barrymore, whose screen credits include the "Charlie's Angels" movies and "E.T. The Extra-Terrestrial," visited the floor of the Chicago Board of Trade Monday afternoon, saying she discussed the impact of rising food prices on the poor.

"I wanted to bring awareness to it because it's not something we think about," she said.

There has been a 40 percent rise in commodity prices since the middle of last year, caused in part by skyrocketing energy costs and rising consumer demand in developing countries like India and China, a World Food Program statement said.

The Rome-based agency has an annual budget of about $3 billion, but it said it needs $500 million more this year than it anticipated to help feed the world's poor because of the rising food and energy prices.