The decision by Europe's highest court that obesity can be a disability will only make a bad problem worse. Too many people in rich countries are already overweight. Giving them legal grounds to feel righteous about their condition, regardless of its causes, will almost certainly expand their ranks.

The case brought to the European Court of Justice involved Danish child-minder Karsten Kaltoft, fired by the municipality of Billund in 2010 after 15 years of service. The town attributed the firing to redundancy, but Kaltoft, who is 172 cm tall and weighs 160 kg, claimed his employer got rid of him because he was overweight: his weight was mentioned in the conversations that preceded his dismissal. The court was asked to decide whether that would have violated a 14-year-old European Union directive banning discrimination against people with disabilities.

The matter turned on whether obesity qualifies as a disability. It's not expressly described as such in any Danish or European statutes. But the court ultimately sided with an opinion filed by Advocate General Niilo Jaaskinen. He argued: