Alan Thicke, second from right, with his “Growing Pains” TV family, from left, Kirk Cameron as Mike, Joanna Kerns as Maggie, Jeremy Miller as Ben and Elizabeth Ward as Carol. (AP)

Alan Thicke, a television mainstay as writer, composer of theme songs, host of game and late-night shows and, most notably, the wisdom-dispensing patriarch of the long-running sitcom “Growing Pains,” died Dec. 13 in Los Angeles. He was 69.

The Canadian-born performer, who also appeared on soap operas (“The Bold and the Beautiful”) and reality TV shows (“Unusually Thicke”), reportedly died after a heart attack. Carleen Donovan, a publicist for Mr. Thicke’s son, pop singer Robin Thicke, confirmed the death to the Associated Press.

“Living with Alan was like being on an endless est seminar,” the first of his ex-wives once said. But his compulsive work habits, amiable public persona and quest for self-improvement propelled him from Canadian Broadcasting Corp. gofer to his home country’s leading media personality within a decade.

Along the way, he wrote comedy and sketches for high-profile TV specials in Hollywood, co-wrote the theme for “Wheel of Fortune” and sitcoms including “The Facts of Life” and “Diff’rent Strokes,” and helped craft the Norman Lear-produced “Fernwood 2-Night” (1977), a satire of low-budget community talk shows that doubled as a send-up of middle-American values and prejudices. “It was way ahead of its time, predating the emergence of the great ’80s era of irony,” said cultural scholar Robert Thompson.

In 1983, Mr. Thicke made a legendarily disastrous attempt to dethrone NBC’s Johnny Carson as the undisputed ratings giant of late-night television. The star said his abilities as a self-described “schmoozer” did not translate well into a genre that depends on a host’s balance between killer comic instincts and self-deprecation as well as talent for engaging with a guest.

Alan Thicke and Tanya Callau in 2006. (Mario Anzuoni/Reuters)

Washington Post TV critic Tom Shales called him a “cut-rate David Letterman” who resorted to tired quips about artificial insemination and test-tube babies. “The ‘e’ in Thicke is silent; Thicke should be, too,” he concluded. “Perhaps it’s time to increase security along the Canadian border.”

Mr. Thicke later told the A.V. Club, an entertainment website, “We made the terrible mistake of having an entire promotional campaign that said, ‘We’re going to take on Johnny and beat him, and nobody’s ever been able to do it.’ That was an outrageous thing for an unknown, semi-talented, no-name Canadian, a terrible position for him to take against an American broadcasting icon. . . . It wasn’t until Chevy Chase and Magic Johnson came along that the stench of ‘Thicke of the Night’ began to dissipate.”

After that debacle, Mr. Thicke plunged into emceeing and acting work and got the leading role on ABC’s “Growing Pains” in 1985. Mr. Thicke played Jason Seaver, a psychiatrist who moves his practice into his home to help raise his children while his wife focuses on her reporting career. Like other smash sitcoms “The Cosby Show” and “Family Ties,” “Growing Pains" was a throwback to the conventional nuclear families of 1950s TV, Thompson said.

Immune to the tepid reviews, “Growing Pains” remained a viewer favorite over its seven-year run, in part because of an appealing cast that included Joanna Kerns as Mr. Thicke’s wife and teen heartthrob Kirk Cameron as a son.

“Loved it,” Mr. Thicke told the A.V. Club. “Proud of it. Proud of what it stood for. I share the corny family values espoused on that show. . . . So if that’s what goes on my tombstone, I’m perfectly comfortable with it.”

Mr. Thicke was born Alan Willis Jeffrey in Kirkland Lake, Ontario, on March 1, 1947. He was 6 when his parents divorced, and he took the surname Thicke from his stepfather, a physician.

The family moved around, and Mr. Thicke said he cultivated an outgoing personality to make friends. “I was precocious in school and skipped two grades,” he told the Toronto Star. “But that meant I was the youngest guy and girls weren’t paying any attention to me, and I wasn’t big enough to play sports. So when they’d ask, ‘What dork wants to host the talent show?’ I would say, ‘Me. I’m the dork.’ ”

Alan Thicke in 1992 (Julie Markes/AP)

He entered the University of Western Ontario with the intention of studying medicine but his evenings spent drinking (“I threw up all over southern Ontario”) and his deepening interest in entertainment derailed those plans.

He ingratiated himself into the CBC and contributed comic material to sitcoms and hosted radio shows. In 1970, he married singer and actress Gloria Loring, settled in Los Angeles and landed work as a writer on TV specials hosted by Richard Pryor, Sammy Davis Jr. and Barry Manilow, among others.

In the mid-1970s, his stint as a TV producer in Canada of “The Bobby Vinton Show,” starring the pop crooner of “Blue Velvet,” brought him to the attention of Lear, the co-creator of “All in the Family” and other groundbreaking sitcoms. “He said he wanted to meet the guy who could actually make Bobby Vinton funny,” Mr. Thicke told the Star. “That was me.”

In 1977, Lear tapped him to help produce and write for “Fernwood 2-Night,” which had spun off from Lear’s hit soap opera parody “Mary Hartman, Mary Hartman.” “Fernwood” was set in Ohio and featured Martin Mull as the narcissistic host, Fred Willard as his dimwit second banana, and a house bandleader (Frank De Vol) with a poor sense of tempo.

Mr. Thicke also worked on the short-lived sequel “America 2-Night” (1978), which was based in Alta Coma, Calif. (“the unfinished furniture capital of the world”). Meanwhile, Mr. Thicke continued to work on Canadian programs, notably his self-titled variety show. It won high ratings but critical drubbings from reviewers who found Mr. Thicke flavorless. “Like Canadian Merv Griffin,” Toronto Sun TV critic Jerry Gladman wrote.

His marriages to Loring and Gina Tolleson, a model and television personality, ended in divorce. In 2005, he married model Tanya Callau, who was 28 years his junior. Besides his wife, survivors include two sons from his first marriage, Robin Thicke and Brennan Thicke; a son from his second marriage, Carter Thicke; and a brother, television writer and producer Todd Thicke.

After “Growing Pains,” Mr. Thicke hosted a game show (“Pictionary”) as well as comedy specials, awards ceremonies and beauty pageants. He also popped up on series including “How I Met Your Mother” and “Fuller House.”

His work as the creator of musical earworms for sitcoms proved one of his most lucrative legacies. “I get ringtone royalties,” Mr. Thicke told the A.V. Club in 2010. “Apparently what happens is, you get college kids after a couple of rounds of Beer Pong, and they start to bet each other who can remember the most lyrics to an iconic sitcom, and they order it up on ringtones, and I get 11 cents. It doesn’t keep up with the current state of the global economy, but it’s always a pleasant little surprise in the mail.”