The retailer is attempting to trademark the phrase.

America’s Healthiest Grocery Store wants to go global.
Whole Foods has reportedly filed an application with the U.S. Patent and Trademark Office requesting to trademark the phrase “World’s Healthiest Grocery Store.” The application, which Brand Channelreports is dated June 23, suggests that Whole Foods  WFM -9.01%  plans to rebrand itself, if the trademark is accepted.
USPTO generally doesn’t grant superlative trademarks denoting that something is the best or the greatest in some field. In 2012 Dunkin’ Donutsapplied to trademark the phrase “Best coffee in America,” and it was rejected. The coffee chain has been using that slogan since 2006 and, though they can still use it, they can’t keep others from doing so as well. The U.S. Patent and Trademark Office denied it on the grounds that it was “mere puffery.”
Whole Foods has previously applied for a similar slogan, “America’s Healthiest Grocery Store.” At first, it was denied. The patent and trademark office eventually withdrew its refusal when the grocery chain pointed out that other registrations included the same phrasing, “America’s Healthiest,” though the office did ask that Whole Foods drop the words “Grocery Store” from the trademark.
This situation will likely result in a similar fight. However, it may be significant that Whole Foods doesn’t operate worldwide. It only has locations in the U.S., U.K., and Canada, so claiming that it’s the “World’s Healthiest Grocery Store” may be a bit superfluous.