The company is the first national grocery chain to set a deadline for full GMO transparency, i.e. that all foods containing GMOs will be clearly labeled by 2018. Whole Foods says it will work in collaboration with its suppliers as they transition to sourcing non-GMO ingredients or to clearly labeling products with ingredients containing GMOs. The five-year lead time is due to the complexities surrounding GMO products, the company says. The prevalence of GMOs in the US, coupled with a lack of labeling guidelines makes it very difficult for grocery stores to source non-GMO choices, according to Whole Foods.