'Gilbert Grape' Star Darlene Cates Dead at 69

Darlene Cates, who played the Gilbert's mom in "What's Eating Gilbert Grape," has died.

We're told Darlene died Sunday morning in her sleep ... this according to family.

She was discovered by the screenwriter of the movie, Peter Hedges, after seeing her on "Sally Jessy Raphael." The show was titled, "Too Heavy to Leave Their House." Darlene talked about obesity and the pelvic infection that caused her to gain nearly 150 pounds.

Hedges offered Darlene the role of Leo DiCaprio's morbidly obese mom in 'Gilbert Grape,' which became an instant classic.

RIP