Active investor Jana Partners has added a fifth nominee to its candidates for Whole Foods Market's (WFM) board of directors, as it ramps up pressure on the grocer to increase profits and lift its slumping stock, Reuters reports.

Jana nominated Celeste Clark, the once chief sustainability officer at Kellogg (K) - Get Report.

Clark joins a list of nominees presented by Jana including former CEOs of Gap (GPS) - Get Report and Harris Teeter (HTSI) .

Jana which today lowered its stake in Whole Foods to 8.2% from 9%, has been urging the company to shake up management, increase profitability and stabilize its stock price.

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