Long-time PepsiCo (PEP -0.41%) CEO Indra Nooyi announced on Aug. 6 that she would step down from her role as chief executive. Effective on Oct. 3, PepsiCo president Ramon Laguarta will take over for Nooyi, who served for 12 years as CEO and was with the beverage and snack giant for 24 years.

Nooyi's departure once again highlights the extreme gender imbalance among leaders of Fortune 500 companies. Out of the companies in the Fortune 500 list of top businesses, the percentage with women serving as CEOs has stayed stubbornly steady at about 5%. After what seemed to be solid progress in 2017, 2018 was a disappointing year, with numbers falling back toward more typical recent historical levels.

Chart showing number of women CEOs in Fortune 500 companies.

Data source: Fortune. Chart by author.

Nooyi has been one of the most influential executives to lead a Fortune 500 company. She was instrumental in making sure that PepsiCo was ahead of the shift to healthier snack and beverage options, spearheading innovative initiatives to make changes to ingredients, portion sizes, and marketing campaigns to revamp the company's entire image. That move proved prescient, as companies across the industry are now scrambling to address concerns from healthcare advocates about the adverse health impacts of sugary carbonated beverages.

Portrait of Indra Nooyi.

Indra Nooyi. Image source: PepsiCo.

Nooyi was also an advocate for diversity. Having grown up in India, the CEO understands the challenges that women and minorities face and appreciates the value of diverse backgrounds. She answered the call to corporate service without sacrificing her identity or integrity.

Laguarta has a long history at PepsiCo as well and should be able to continue Nooyi's legacy. But for those who'd like to see more women in the executive suite, Nooyi's departure and replacement is just another step in the wrong direction.