The average American waistline has grown by 7 inches for women and 4 inches for men since 1960.
The width of an airplane seat: still between 17 inches and 18 1/2 inches since 1958.
"If you go to a movie theater or you get on a train, the seats are actually bigger than on an airplane," said Brandon Macsata, executive director of the Association for Airline Passenger Rights.
"It's not the size of a person's butt that's the issue. It's the size of the seat the butt is sitting in."
The issue of cramped space on airplanes squeezed into the news again last weekend when actor and director Kevin Smith was ejected from a Southwest Airlines flight because he was too big for a single seat. The angry director of the movies "Clerks" and "Mallrats" set off a Twitter maelstrom, which the airline countered with a $100 voucher and two seats on a later flight.
Some businesses have caught up with the nation's expanding girth. Car companies are positioning pedals farther apart for bigger and wider feet, toilet seats have gotten larger, and even trendy clothes come in super-big sizes.
But not only have airlines kept seats the same size for five decades, many now require larger passengers to purchase extra seats. And legroom is shrinking, according to Matt Daimler, founder of seatguru.com.
Low-cost carriers like AirTran Airways and Spirit Airlines offer only 30 inches between seats, while domestic flights on major airlines generally provide 31 inches and international flights 32, he said.
A few airlines offer more, such as JetBlue, which has 34 inches between seats. United Airlines allows passengers to pay an extra $9 to $199 for 35 inches to 36 inches, and JetBlue offers some seats with 38 inches for $10 to $30 per flight segment.
For comparison, Canada has had a one-person, one-ticket policy since 2008 — meaning airlines can't charge larger passengers extra, even if they take up multiple seats.
Daimler, who is 6-foot-1 and can comfortably put armrests down, flies on a regional carrier from New York to Virginia to visit family.
"If I bring a book, I can't put it in the seatback pocket," he said. "But for 45 minutes and $59, I'd rather do that. I wouldn't do that on a three-hour flight."
The situation is difficult and embarrassing for "people of size," said National Association to Advance Fat Acceptance spokeswoman Peggy Howell.
"We never know if we're going to be the next one called out of line or told we have to buy a second seat," she said.
Howell and two girlfriends purchased four seats for a trip to Hawaii but were dismayed when the armrests in their row couldn't be raised.
In 1960, 14 inches was the average buttocks width for men, and 14.4 for women, according to the Centers for Disease Control and Prevention. Average waist sizes were 30 inches for women, 35 for men. By 2000, those waist sizes had expanded to 37 inches and 39 inches. The CDC no longer tracks buttocks width.
Average height also has increased an inch in the past 50 years, adding to our collective airborne compression.
Read the full story at sacbee.com