Robert Downey Jr. Relapses!

Last night on The Tonight Show, Robert Downey Jr. admitted to Jay Leno that he has relapsed. Relax - he has only begun smoking again.

But, wait - don't let's be relaxed about it. Smoking is as deadly an addiction as there is - no substance is associated with more death than smoking. And Downey seemed appropriately guilt-tripped by Leno bringing his "weakness" up. After all, Downey has a 17-year-old son, and says he wants more children. So, (a) he wants to stay alive, (b) he doesn't want to be a poor role model whose own child/children possibly imitate his bad example and start smoking.

But, wait again, this addiction stuff is a little confusing. Downey was famously addicted to drugs and alcohol - leading him to jail and almost ruining his career (which he has now resuscitated by becoming among Hollywood's most successful stars).

So can you choose which addictions you relapse to?

Think before you answer - this is actually a quite difficult philosophical-medical question. If addiction is losing all control, then why did Downey start smoking again, but not using drugs or alcohol? How do you "choose" to do that?

Is it possible that he thought - "Well, I can't blow my career by taking drugs and drinking, but relapsing to smoking isn't so bad if I have to pick one" (he told Leno he started smoking again because he was tense - and that he has quit "a hundred times").

Sidebar: One possibility is that Downey has started drinking and using drugs again, but he hasn't lost such control that he has been discovered. I don't wish this on him or recommend it. But it is a logical possibility.

Which brings up Downey's weight. He looks as trim and muscular (which his roles in the "Iron Man" and "Sherlock Holmes" franchises require) at 45 as ever. Many of us have lots of trouble controlling our weight - how does Downey do that, but fail at staying quit of cigarettes?

"Wait," you might say - "what do eating and drug addiction have to do with one another?"

Well, according to Downey, he quit drugs out of his concern for how they made him eat. I kid you not!

The fast food epiphany happened in 2003 when the "Iron Man" star was driving a car piled with "tons of f---ing dope," Downey Jr. told Britain's Empire magazine. The actor decided to pull over for a burger and everything changed.

"I have to thank Burger King," he said. "It was such a disgusting burger I ordered. I had that, and this big soda, and I thought something really bad was going to happen." Downey Jr. says he then tossed all of his drugs into the ocean, deciding right then and there to clean up his act.

So, as opposed to the standard recovery stories, Downey wasn't saved by rehab, by AA, by love of family - but because he didn't want to eat another disgusting Burger King burger and soda (and he didn't even have fries!).

Man, this addiction is a tough nut to crack - it seems to involve a whole set of almost conscious choices and values - like self-disgust over eating poorly and losing one's figure. By the standard of mindfully controlling his diet, Downey is among the most self-controlled people in America.

If nicotine made Downey eat crappy food, would he never smoke again? Remember, there can't be a pot-bellied Iron Man.

When we ask what's important in a person's life, for Robert Downey Jr., eating well and remaining attractive are his supreme values, so that he seems to evaluate substance abuse in terms of how it relates to staying trim. This makes sense in his world - for Downey, no other habit-addiction would end his career more assuredly than overeating or anything that contributes to it.