From Scientific American:
Morbidly obese men tend to have more breathing difficulties than morbidly obese women, partly because they have much larger waistlines, a new study suggests.
Dr. Gerald S. Zavorsky from McGill University Health Center, Montreal, and colleagues examined the effect of the so-called “waist-to-hip ratio” on breathing in 25 morbidly obese adults scheduled for bariatric (stomach) surgery.
As the name implies, the waist-to-hip ratio is a calculation of a person’s waist circumference divided by their hip circumference. People with a high ratio have an “apple-shaped body,” whereas people with a low ratio have a “pear-shaped body.”
More here.