Diane Keaton’s close friend is giving insight into the actress’s health before her death.

“I saw her two or three weeks ago, and she was very thin,” Grammy and Oscar-winning songwriter Carole Bayer Sager told People in an interview published Sunday, one day after Keaton died at age 79.

“She had lost so much weight,” Sager, 81, added about Keaton.

Diane Keaton seen out in Los Angeles in May 2024. GC Images
Diane Keaton out and about in Los Angeles in Aug. 2024. GC Images

Sager also explained that she saw Keaton less this year because the “Father of the Bride” star moved to Palm Springs after her home was damaged in the California wildfires in January.

“She was down there for a while, and when she came back, I was kind of stunned by how much weight she’d lost,” Sager said.

Carole Bayer Sager during 2003 Society of Singers ELLA Awards. WireImage
Carole Bayer Sager attends VIOLET GREY x Victoria Beckham Beauty LA Dinner in Beverly Hills in Nov. 2019. Getty Images for VIOLET GREY
Diane Keaton in an Instagram photo. Instagram/@diane_keaton

The songwriter, who helped Keaton make her only single, “First Christmas,” which was released in Nov. 2024, described the late actress as “a magic light for everyone.”

“I just loved her,” Sager shared. “She was so special, she just lit up a room with her energy. She was happy and upbeat and taking photographs of everything she saw. She was completely creative; she never stopped creating.”

Another friend, a film executive, told People that Keaton “was funny right up until the end.”

Diane Keaton appears at the Ralph Lauren Spring 2023 Fashion Experience in Pasadena, Calif., on Oct. 13, 2022. Chris Pizzello/Invision/AP

“She lived exactly how she wanted to, which was on her own terms, surrounded by the people and things she really loved,” the pal stated, adding that Keaton “kept a close circle and she liked it that way” in the final few years of her life.

“She had this way of making even ordinary moments feel special,” Keaton’s friend also said. “That was just who she was.”

Diane Keaton walking her dog in October 2024. Javiles / Bruce / BACKGRID
Diane Keaton on a walk with her dog in Brentwood, Calif. in Oct. 2024. Javiles / Bruce / BACKGRID
Keaton, whose career spanned more than half a century, died Saturday in California, her family confirmed. A cause of death was not disclosed.

Keaton’s health allegedly “declined very suddenly” in the last few months.

“It was so unexpected,” a friend of Keaton’s told People Saturday, “especially for someone with such strength and spirit.”

Diane Keaton at the “Book Club: The Next Chapter” premiere in New York City in May 2023. Evan Agostini/Invision/AP
Diane Keaton arrives at the 13th Annual Gala in the Garden in Los Angeles in Oct. 2015. Jordan Strauss/Invision/AP
The friend added that Keaton’s health decline “was heartbreaking for everyone who loved her.”

Keaton never disclosed if she was battling any illness. She previously survived two bouts with skin cancer and an eating disorder.

Diane Keaton in a photo with her dog. Instagram/@diane_keaton
The “First Wives Club” actress last posted to her Instagram on April 11, sharing a photo with her Golden Retriever, Reggie. She had not been seen publicly in six months.

Keaton is survived by her two children, Dexter, 29, and Duke, 25, whom she famously adopted after her 50th birthday.