Americans’ waistlines are widening, finds a new study, even as our weight appears to be holding steady. The findings are important for cancer risk — along with other diseases — because while obesity is a clear cause of cancers, abdominal obesity may also independently increase risk.
The study, published in JAMA, found that Americans’ average waist circumference increased progressively slightly more than an inch from 1999 to 2012. During those years, waists bumped up from 37.6 to 38.8 inches.
Prevalence also increased, with over half of Americans now having abdominal obesity. Prevalence rose from 46 percent in 1999 to 54 percent in 2012, among both men and women.
The study included 32,816 participants who were part of multiple national surveys from 1999-2000 to 2011-2012. Previous analyses of data from the same surveys show that obesity did not change much from 2003 to 2012, the authors write.
Why that would be is unknown, but what is known now is that not all body fat is the same. Location matters.
Some research suggests that visceral fat is an independent risk factor for certain cancers. It also may indicate higher risk of metabolic abnormalities that can play a role in type 2 diabetes and other chronic diseases. Even people at a healthy BMI may be at increased risk if they have too much visceral fat, some research suggests.
For women, a waist measurement of 31.5 inches or more indicates higher cancer risk. For men, a waist measurement of 37 inches or more indicates high risk.
Waist circumference, like BMI, are just indicators of having a healthy amount of body fat. But routinely tracking your weight and waist circumference checking give you information about your risk.
You can learn more on healthy waist circumference and calculate your BMI here.