J. Robert Birnhak, 95, of Bala Cynwyd, a lawyer who teamed up with his wife, Marilyn, to create and direct Weight Watchers of Philadelphia, Inc., and a philanthropist who supported causes here and in Israel, died Sunday, July 14, of complications from pneumonia at his home.

Mr. Birnhak and his wife first learned of the weight-loss industry in 1963 while living in New York. They signed up for a class and lost weight, at the same time gaining the fundamentals for a vocation in Philadelphia, his wife’s hometown.

They were so impressed with the program taught by Weight Watchers founder Jean Nidetch that when they were offered the chance to buy a franchise, they grabbed it.

Mr. Birnhak became the franchise’s director, his wife, the president. Son John joined the business in 1983, and before her death from breast cancer in 2004, daughter Tracey Birnhak was vice president of marketing and business development for 11 years.

The business grew from a small operation in 1964 with two meetings and eight members in Mount Airy, to a firm with 500 employees serving up to 35,000 members each week at 600 meetings in the early 1990s. The target areas are southeastern Pennsylvania and South Jersey. It now has 20,000 members and 450 meetings.

Mr. Birnhak’s son, John, now the franchise president, said his father was “the operational person.”

“He got the leases, scouted for meetings, handled the staff, money, bookkeepers, and lawyers. My mother ran the meetings and trained the coaches. At times, he had to be the leader, the receptionist, the plumber. You do what you have to do.”

Born in the Bronx to Samuel and Rae Birnhak, he graduated from DeWitt Clinton High School in the Bronx and Brooklyn College. He received a law degree and a post-graduate master of laws degree, both from New York University.

A World War II veteran, he served in the Philippines and Australia with the Army Signal Intelligence Corps. After his service, he returned to New York, working first as an insurance investigator and then as an assistant district attorney for the Queens County District Attorney’s Office.

Mr. Birnhak was elected an alderman for the Queens district in which he lived and was president of the Wagner Democratic Club . He was elected a New York State Assemblyman in 1964 and shared a desk with Shirley Chisholm.

The Birnhaks had three children, whom they raised in Laverock. Later, the couple moved to Bala Cynwyd. They had a second home in Margate. Mr. Birnhak’s wife died in 2018.

He was a supporter of Jewish Federation of Greater Philadelphia and on the boards of the Beth Sholom Congregation in Elkins Park, American Friends of Magen David Adom, American Associates of Ben Gurion University of the Negev, and the Madlyn and Leonard Abramson Center for Jewish Life in North Wales, where the Birnhak Transitional Care Unit was named in the family’s honor.

He was instrumental in creating the 35-bed Abramson Senior Care, Birnhak Transitional Care Unit at Lankenau Medical Center in Wynnewood. The unit, which opened July 17, three days after his death, provides short-term rehabilitation, medical, and nursing care for elderly patients recovering from surgery, injury, and stroke in a homelike setting.

Bridget Therriault, a spokesperson for Main Line Health, said the health system and Abramson Senior Care, “will feel the tremendous loss of Mr. Birnhak’s treasured friendship.”

Because of Mr. Birnhak and his wife’s investment in Birnhak Transitional Care on Abramson’s North Wales campus and Birnhak Transitional Care at Lankenau, “we are able to ensure the availability of high-quality and compassionate transitional care for seniors across our area for generations to come,” Therriault said.

He was also a benefactor for the Abramson Cancer Center – Perelman Center, the Philadelphia Theatre Company, and the National Liberty Museum.

He and his wife created the Philadelphia Police and Fire Department Weight Watchers Battle of the Badges Competition.

Besides his son, Mr. Birnhak is survived by a daughter, Valerie; five grandchildren; a brother; and nieces and nephews.

Services were Tuesday, July 16, with interment at Roosevelt Memorial Park, Trevose.

Memorial contributions may be made to Abramson Senior Care, 1425 Horsham Rd., North Wales, Pa. 19454.