In 1994, the actress opened up to PEOPLE about her longtime struggles with obesity

Darlene Cates, best remembered as the actress who played Johnny Depp and Leonardo DiCaprio‘s obese, housebound mother in the 1993 film What’s Eating Gilbert Grape, died in her sleep on Sunday morning at age 69.

In 1994, the actress — whose weight at one point shot up to nearly 600 pounds — opened up to PEOPLE about her longtime struggles with obesity and how overcoming her self-consciousness unexpectedly led to the launch of her Hollywood career.

“Stop putting things off until you’re skinny!” urges Darlene Cates with hard-won conviction.

Six years ago, weighing nearly 600 lbs. and weakened by chronic illness, she was so depressed she wouldn’t leave her modest brick home in Forney, Texas.

”I felt forsaken by God,” she says.

Today, though still extremely heavy at 5 ft.9 in. and 520 lbs., she appears on talk shows and has a central role in the new movie What’s Eating Gilbert Grape?, starring Johnny Depp and Juliette Lewis. Though she has never acted before, Cates gives a touching performance as Depp’s housebound mother, a woman ”beached,” in Gilbert’s words, ”like a whale,” yet able to maintain her dignity.

It is a role that rang true to Cates, 46, who believes that ”what the scales say doesn’t have a thing to do with your value. You can be productive and attractive — maybe not to everybody, but, by god, to some.”

Her husband, Bob, 56, has stuck by her for 31 years, and their three children — Sheri, 28, Mark, 24, and Chris, 22 — provide a support system, just like the movie mother’s kids. ‘

‘I’m proud of her,” says Bob, a postal worker. ”She’s always had that pioneer spirit.”

And she has needed it. Cates grew up in the panhandle town of Dumas, Texas, the daughter of a homemaker and a gas-station attendant who divorced when she was 12. Two years later she met Bob and lied to him about her age. After a year’s courtship they married; he was 25, she 15.

”I wanted someone to give me attention,” she says.

Unfortunately, Bob’s career as a Marine took him away often, with two 13-month tours in Vietnam as a helicopter machine gunner. Each time he left, Darlene, who says she was ”pleasingly plump” as a teenager, took solace in food. Her overeating, compounded by a thyroid condition and slow metabolism, led to substantial weight gains.

'What's Eating Gilbert Grape' film premiere, Los Angeles, USA
Credit: BEI/Shutterstock

Then, in 1986, pelvic infections caused by a Dalkon Shield worsened and kept her bedridden for two years, during which she gained 150 pounds. Cates, feeling hopelessly sick and overweight, often found herself contemplating suicide.

When she confided in her doctor, he recommended Prozac, an antidepressant that, she now says, ”turned my life around.”

In 1992, she finished high school via correspondence courses and emerged from her house after a five-year period of reclusion, accepting an invitation, proffered through a support group she belonged to, to appear on a Sally Jessy Raphael show about overweight people who don’t leave their homes.

At first she wanted to say no. Then, she says, she heard ”this voice” pushing her.

Viewers responded with cards and gifts, and a month later she was invited back.

Grape screenwriter Peter Hedges caught her first Sally appearance and showed a tape to director Lasse Hallstrom.

”He loved her from the minute he saw her,” says Hedges.

In fact, the role of Momma was expanded after Hallstrom discovered Cates could act.

”She gets into the emotion very quickly,” he says.

Cates fondly recalls the four-month shoot in and around Austin, Texas, where everyone, including Depp, treated her with affection.

”He would always come up and give me a kiss,” she says. Depp himself sounds smitten. ”You look into those eyes and melt,” he says. ”She is, like, my prom queen.”

Cates wants to act again — and has an offer. She also hopes to lose weight, but, she says, ”God has his own timetable.”

After all, she reasons, ”all this stuff happened to me because I’m fat.”