Chipotle Mexican Grill is facing a lawsuit from shareholders over allegations of inadequate portion sizes. The lawsuit claims that the restaurant chain's serving sizes do not align with customer expectations and have led to substantial losses for investors. This legal action follows a recent upgrade in Chipotle's stock rating, which has sparked investor interest regarding the company's future performance. The lawsuit is part of a broader trend of legal challenges facing food companies, including a separate class action against Subway related to misleading advertising of its cheesesteak sandwich. Additionally, various law firms are actively encouraging investors from several companies, including PACS Group, Inc. and Domino's Pizza, Inc., to join class action lawsuits due to reported financial losses.