Was it when he played troubled T. J. Latimer in the angst-ridden Family (1976-77)?
Shipwreck survivor Fred Robinson in The Swiss Family Robinson (1975-76)?
As early as his brief sitcom appearance as Paul Sorvino's kid in We'll Get By (1975)?
Certainly by the time he landed the role of troubled Tommy Bradford in Eight is Enough (1977-81), Willie Aames and his muscles were superstars.
Intensive buddy-bonding with the dreamy Scott Baio on Charles in Charge followed (1984-1990), though in order to keep viewers focused on Scott's dreaminess, the producers had to minimize Willie's buffness. They made his character, Buddy Lembeck, stupid, the butt of jokes rather than the source of sighs.
Willie thankfully never sang, but that didn't keep the teen magazines from going into hysterics about his incredible talent -- by which they meant physique.
After Charles, drug and alcohol addiction took their toll, and Willie's acting career fizzled. A stint as Christian fundamentalist superhero Bible Man didn't help him regain his followers or his fame. In 2005, he produced, wrote, directed, and starred in The Public Life of Sissy Pike, about a Christian fundamentalist girl.
There are nude photos of Willie Aames on Tales of West Hollywood.