Chipotle has announced it has become the first major US restaurant chain to make that switch to a menu free of genetically modified organisms (GMO).

It announced yesterday that the 46 ingredients used in its c1,800 sites were now free of GMO and said that the move would not result in significantly higher ingredient costs or a raise in prices across its estate.

In 2013, Chipotle became the first chain to label all GMO foods it served, and back then expressed a desire to eventually eliminate GMO foods altogether. Most of the corn and soybeans grown in the US and across the world are genetically modified.

Chipotle founder and co-chief executive Steve Ells said: “Though many countries have already restricted or banned the use of GMO crops, it’s clear that a lot of research is still needed before we can truly understand all of the implications of widespread GMO cultivation and consumption. While that debate continues, we decided to move to non-GMO ingredients.”

The company said its small ShopHouse Southeast Asian Kitchen chain had also become GMO-free.