The obesity rate in the U.S. remains relatively steady, but that doesn't exactly mean Americans are slimming down.
In fact, a new study from the U.S. Centers for Disease Control and Prevention says Americans are actually going up in size. The study says women's waistlines are getting bigger, with the average increasing 1.5 inches between 1999 and 2012. During that same period, men didn't see quite as big of an increase, rising just 0.8 of an inch. The national average waist size went from 37.6 inches to 38.8 — up 1.2 inches.
Still, it's important to note the study mentions obesity rates have remained fairly steady. So how does that happen, yet waistlines expand?
Turns out, even the researchers lack an answer. Dr. Earl Ford, CDC medical officer and lead author of the study, told NPR, "We're a little bit puzzled for explanations."
But, as HealthDay points out, they at least have an idea: "Researchers speculated that sleep disruption, certain medications and everyday chemicals known to be endocrine disruptors may possibly play a role." Also, a doctor from Washington University in St. Louis says aging baby boomers with slower metabolism and decreased muscle mass might also be a factor.
The Boston Globe writes an increase in medications like antidepressants, not being active enough and sleep deprivation could all be causes for "increased belly fat."
The health issues linked to obesity are widely reported, but researchers say waist size also plays a significant role.
The Mayo Clinic notes "apple shaped" individuals, those with bigger waist sizes and smaller hips, have more health problems than "pear-shaped" individuals, or those with smaller waists and bigger hips.
But a bit of good news — a study earlier this year also from the CDC reported obesity in children has dropped significantly in the past decade. Eight percent of 2- to 5-year-olds were obese in 2012 compared to 14 percent in 2004.
To get an accurate reading of your waistline, researchers say stand up and place a measuring tape around your stomach, just above your hip.