The healthy living lifestyle of Boulder, Colorado, is well-known across America.

Everywhere you go in the town people are cycling, or hiking, or skateboarding. Restaurants and cafes are full of gluten-free, organic produce, and every supermarket has a bewildering array of supplements and vitamins.

The beautiful Rocky Mountains, the famous Flatirons, and the high altitude are draws for anyone interested in fitness and the outdoors, including some world class athletes.

But the body beautiful here hides a less well-known trend.

The rise of eating disorders including anorexia and bulimia is happening across America, among both men and women. But in Boulder this development is particularly intense.

The BBC's Jack Garland gained unique access to a group of eating-disorder patients to examine the pressures on them to attain an athletic image so famous here they call it, the "Boulder Body".

You can watch all the stories from BBC's Pop Up and find out more about project on the behind-the-scenes blog.