They might be eating as much junk as the overweight people are, but because of chronic gut issues, they are not absorbing nutrition, even calories. (greensmoothiegirl.com)
You don't necessarily have to have noticeable gut symptoms to have an underlying chronic gut issue. (mindbodygreen.com)
If someone comes in with chronic issues, especially chronic gut issues, there's a few things I like to test initially. (bengreenfieldfitness.com)