Whole Foods Market is struggling to increase sales after six straight quarters of same-store sales declines. The chain plans to close nine stores and increase use of customer data to improve results.

The chain has been working for months to remove its "Whole Paycheck" moniker and attract a younger clientele. Co-founder John Mackey notes the retailer is "doubling down" on its most loyal customers and "examining every aspect of [its] retail operations." The company expects the closures of the stores, which are smaller, older acquisitions, will improve results. It is also partnering with consumer data company dunnhumby to use its shopper information to improve merchandising and personalize its offers, reports FortuneFull Story

Related: Whole Foods to Open 365 Store in Brooklyn; Whole Foods to Close Kitchen Food-Prep Facilities.