The floor beneath the feet of some 20 Weight Watchers members collapsed at a clinic in Sweden.

The participants in the fat-loss programme had gathered for a weigh-in in the town of Växjö on Wednesday night.

However the numbers on the scales weren't the only thing dropping.

"We suddenly heard a huge thud; we almost thought it was an earthquake and everything flew up in the air," one told the Smalandsposten newspaper. "The floor collapsed in one corner of the room and along the walls."

No one was injured in the incident, and the meeting concluded in another room.

But the damaged floor has spelled the end for the clinic's current building.

"We're going to have to find a replacement premises," Weight Watchers consultant Therese Levin told the paper.