The natural and organic market has grown by leaps and bounds over the past two decades. No grocer has been more synonymous with the movement than Whole Foods Market, Inc. (NASDAQ:WFM). But Whole Foods is no longer the only player in the game, and there are rivals that are looking to seize on such a large opportunity.

Two companies in particular have shown a peculiar ability to become more and more popular with shoppers: Sprouts Farmers Market, Inc. (NASDAQ:SFM) and Natural Grocers by Vitamin Cottage, Inc. (NYSE:NGVC). After the market closes on Thursday, Natural Grocers will announce its earnings.

So what should investors be looking for to determine whether Natural Grocers will be able to capitalize on the popularity of healthy food? In the video below, The Motley Fool's Brian Stoffel highlights three key variables.

John Mackey, co-CEO of Whole Foods Market, is a member of The Motley Fool's board of directors. Brian Stoffel owns shares of Whole Foods Market. The Motley Fool recommends and owns shares of Whole Foods Market. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.