The Commission will decide by Dec. 9 whether to clear or block the deal.
Google said the combination of its and Fitbit's hardware would increase competition in the sector where players include Apple, Samsung, Xiaomi, Huawei and others.
"This deal is about devices, not data. We've been clear from the beginning that we will not use Fitbit health and wellness data for Google ads," Rick Osterloh, senior vice president for devices and services, said in a statement.
"As we do with all our products, we will give Fitbit users the choice to review, move or delete their data."
The deal has drawn criticism from healthcare providers, wearables rivals and privacy advocates.