"The measuring [for obese customers] really doesn't follow any formula, but the last thing we need is a lid that will not close when the time comes," Davis said.
Even then, oversized caskets cannot always fit into a standard hearse. In that case, Davis said, families sometimes have to get creative with their transportation options.
"They may need an alternative method of transport, like a nice van," he said. "We've also had people use open-box trucks, fire trucks and horse-pulled wagons to carry the casket."
Also, grave plots are usually about 38 inches wide, so if the coffin is wider than the plot, a family must buy two plots, which adds a significant additional expense.
But before grave plots and transportation options, a funeral director must prepare the body.
Realizing the need for assistance to lift overweight bodies during preparation, Katie Hill started marketing the Mortuary Lift, a piece of equipment that lifts and elevates a cadaver with the push of a button. It can also raise certain sections of the remains, which helps when dressing and positioning much heavier bodies, Hill said.
The device can lift up to 1,000 pounds.
"The No. 1 injury in this industry is a back injury," Katie Hill of Cedar Rapids, Iowa, said. "There's no good way to lift deceased remains, and the Mortuary Lift reduces time, eliminates injury and allows women and men to perform at an equal level because there is no difference in strength."
Without such assistance, Hill said, funeral directors sometimes have to ask for help from neighbors, friends and fire and police departments in lifting heavy cadavers.
She has seen her sales grow by more than 20 percent in the past several years.
Lift or no lift, it seems that oversized caskets have likely earned their place in the funeral industry.
"Obesity is a gigantic public health problem, and I think it's going to get worse in adults because there are so many obese children," said Dr. Carla Wolper, a dietitian at the Obesity Research Center at St. Luke's-Roosevelt Hospital in New York. "I don't see the problem getting better for a while."
The result, many funeral directors and casket retailers believe, is that the oversized casket is here to stay.
Davis said it's important to be realistic and work out the details so that, if an alternative method for part of the funeral is needed, everyone will be prepared.
"If funeral directors can figure out [logistics] beforehand," he said, "the person's life can be celebrated with dignity instead of being made fun of or scoffed at."