The nation has lost a key general in the war on obesity. Jean Nidetch, who co-founded Weight Watchers in 1963, has died.

A tribute in The New York Times noted Nidetch was a 214-pound Queens homemaker with a 44-inch waist and “an addiction to cookies by the box” in 1961 when she was prompted to create the organization after a neighbor’s unkind comment about her weight at the supermarket.

“Oh, Jean, you look so good!” the neighbor reported told her. “When are you due?”

That indelicate comment prompted her to drop 72 pounds and incorporate Weight Watchers in 1963 with her overweight husband and two like-minded friends.

Since then, the group has developed thousands of franchises, enrolled millions around the world, and spawned weight-control classes that resembled group therapy sessions. Weight Watchers has also created summer camps for overweight children, a daily syndicated television program, and publishes magazines in America and Britain, among other enterprises.

Weight Watchers went public in 1968, and was sold in 1978 to H.J. Heinz for $71.2 million, The Times reports.

Nidetch, who was president in its early years, was in charge of public relations until 1984. Through her life, she continued to hew to the organization’s manifesto that healthy weight manage requires lifelong lifestyle changes. As recently as 2011 she weighed 142 pounds — as much as she did after her dramatic weight loss in the early 1960s.

She died on Wednesday at her home in Boca Raton, Fla., according to a Weight Watchers spokeswoman. She was 91.