A big part of Chipotle's "Food With Integrity" philosophy is sourcing what it calls "responsibly raised" meat (originally called "naturally raised"). However, "responsibly" and "naturally raised" are not terms regulated by the government, and Chipotle does not require producers to have a third-party certification, such as Certified Organic or Certified Humane. "'Natural' is on the honor system," wrote food expert Marion Nestle in her book What to Eat. "Some producers of 'natural' meats may be honorable, but you have to take what they say on faith."

Chipotle's version of responsibly raised meat has three main requirements: Animals have received no added hormones, no antibiotics ever, and were humanely raised. BuzzFeed asked to see the full definition of the responsibly raised standards, but the company declined to share them. "We struggle with getting people to understand the most basic elements," said Arnold, "and adding details really runs the risk of muddying that understanding further."

When the company can't meet its needs with responsibly raised meat, it uses conventionally sourced meat — meaning it's from animals that were raised with growth hormones, sub-therapeutic antibiotics, and in conditions generally not considered humane — to fill the gap. In 2013, that came out to 7.8 million pounds of its beef (15% of its beef) and 88 million pounds of its chicken (less than 1% of its chicken). (All of the pork served fit their standards of responsibly raised.)

Several food and animal welfare experts recognize Chipotle for its efforts. "My reading of this is that they would like to be sourcing all of their meat from natural, sustainable, antibiotic-free, and cage-free farmers but can’t always get it," said Nestle.