LONDON (AP) _ Roger MacDougall, a screenwriter and playwright who later promoted the diet he used to control multiple sclerosis, has died at a home for actors, the home's administrator said Monday. He was 82.

''He was working on his ideas right up to the day he died,'' said Moira Miller, administrator at Denville Hall in Northwood outside London.

She said she could not provide the cause of his death on Thursday.

MacDougall made his name in the 1950s with ''The Man in the White Suit,'' a script he wrote with John Dighton and Alexander Mackendrick. The satire on materialism starred Alec Guinness.

Although he worked in film, MacDougall's heart was in the theater.

''I am interested in words and ideas,'' he explained. ''Films are all what- happens-next. To me why-did-that-happen is more interesting ... Only in the theater is the writer in control.''

His plays included ''The Gentle Gunman,'' ''To Dorothy a Son'' and ''MacAdam and Eve'' written in 1950; ''Escapade,'' 1952; ''The Facts of Life,'' 1954; ''The Delegate,'' 1955; ''Double Image,'' 1956; ''Hide and Seek,'' 1957; ''Trouble With Father,'' 1964, and ''Jack in the Box,'' 1971.

In the 1950s MacDougall developed multiple sclerosis. The disease, which short-circuits the nervous system, left him nearly blind and in a wheelchair.

To combat the symptoms, he went on a strict, nearly carbohydrate-free diet.

''His diet certainly had effected an enormous remission for him, and he hoped it would help others,'' Ms. Miller said.

In 1963, MacDougall settled in California, where he taught screen writing. Within a few months he was able to transfer from a wheelchair to an electric golf cart, and by the time he returned to England in 1970 he was on his feet again.

He frequently published articles and pamphlets on his diet in an attempt to help others afflicted by the disease.

MacDougall was born in Scotland on Aug. 2, 1910. After graduating from Glasgow University he headed to London and a career as a free-lance writer.

In 1935, MacDougall married Renee Dunlop, who died in 1977.

He is survived by a daughter, Elspeth, of New York; a son, Lindsay, of London, and two grandchildren.