Lesson to public-health campaigners: When selecting a celebrity to represent your health cause, be sure you're thoroughly familiar with your candidate's background and lifestyle.

Consider the case of Garfield the cat, recently chosen to promote the "Sleep Well. Do Well. Star Sleeper" campaign of the National Heart, Lung, and Blood Institute.

Launched in 2001, the effort aims to convince young children and their parents of the importance of a good night's sleep. A cartoon cat is perfectly suited for this audience, right?

Wrong, writes cardiologist Mark D. Fox in the journal Pediatrics. Fox, chief of the medicine/pediatrics section at the University of Oklahoma College of Medicine, Tulsa, commends the campaign goals, but argues that its laconic, dry-witted spokescat is a poor role model for healthy behavior.

The skinny: Writes Fox: "Garfield is a poster child for cardiovascular risk. Although I have no knowledge of his family history, he is clearly obese and sedentary. I shudder to think what his blood pressure and lipid profile are, given the quality and quantity of the diet he consumes."

Fox has also "long suspected that Garfield suffers from clinical depression."

The answer: How does the NHLBI respond? Michael Twery, acting director of the National Center on Sleep Disorders Research, part of the NHLBI, defends his star hire.

Writing in the same issue of Pediatrics, he describes Garfield as doing a bang-up job promoting the sleep campaign.

He dismisses Fox's attack as "catty."