John Kenneth Galbraith, a Canadian-born economist who was considered a giant on the world stage as a Harvard professor, diplomat and adviser to U.S. presidents, died Saturday night at the age of 97.

Galbraith died of natural causes after spending about two weeks in Mount Auburn Hospital in Cambridge, Massachusetts, his son Alan Galbraith told The Associated Press.

Galbraith's resume includes a stint as John F. Kennedy's ambassador to India. He was also an accomplished author, and an adviser to a number of Democratic presidents including Franklin D. Roosevelt and Bill Clinton.

Galbraith's son said his father "had a wonderful and full life."

Galbraith, a world traveller with a legendary wit and sense of humour, began to gain notoriety in the decades following the Second World War.

His book, The Affluent Society, published in 1958, argued that the U.S. economy was based on outdated principles, and was helping individuals become rich while it neglected important public infrastructure such as schools and roads.

Galbraith authored more than 1,000 articles and about four dozen books during his life, mainly on economics, and a personal memoir called A Life in Our Times.

He also wrote a factual account of his time in India, and a work of fiction called The Triumph, also set in India.

Galbraith was born in Iona Station, near London, Ont. on Oct. 15, 1908.

He graduated from the Ontario College of Agriculture -- now the University of Guelph, but then associated with the University of Toronto -- in 1931, moving to the U.S. shortly after, where he attended the University of California and earned a PhD in economics.

He later taught at Harvard from 1934 to 1939 and Princeton University from 1939 to 1942, before taking a position at the federal Office of Price Administration during the war.

He returned to Harvard in 1948 where he remained active until his retirement in 1975.

Galbraith married Catherine Atwater in 1937. The couple had three sons; Alan, Peter and James.