Jean Nidetch
Weight Watchers founder Jean Nidetch has died of natural causes. She was 91. Pictured here, Heather Nidetch at the company's 50th anniversaryCraig Barritt/Getty Images for Weight Watchers

Jean Nidetch, the woman who founded diet company Weight Watchers, has died at the age of 91.

TMZ reports the businesswoman passed away in the Ft. Lauderdale area on the morning of 29 April due to natural causes. According to the Associated Press, her death was confirmed by her son, David Nidetch.

Millions of women around the world have used Weight Watchers' diets to slim down and past celebrity spokespeople have included, Oscar-winner Jennifer Hudson and singer Jessica Simpson.

Nidetch had been overweight since her childhood when she embarked on a mission to get into shape in 1961.

The former Internal Revenue Service employee huddled together a group of her larger friends to form weekly classes in her living room where they would share weight loss tips and offer each other encouragement.

Others hoping to lose weight caught wind of these meetings and in 1963, Nidetch officially founded the company in Brooklyn, New York.

Recalling her visit to a New York Board Of Health seminar shortly before she founded the company when she weighed 214 pounds, Nidetch told The Sun Sentinel in 2011: "The sign said, 'Obesity Clinic'. Those aren't exactly words that make you feel very good.

"But the more I listened to the speaker, the more I thought, 'This makes sense'."

She then began charging her friends $2 (£1.50) to attend the classes at her home but later had a change of heart.

Nidetch told the publication: "But I felt guilty taking their money, so I told everyone they could come as many times as they wanted for the week."

In 1978, Weight Watchers was sold to Heinz Co. for a reported $71m (£68m) but Nidetch continued to act as a consultant to the organisation and has also established scholarships at the University of Nevada in Las Vegas and the University of California in Los Angeles.