Fitbit Under Google: Your Health Data Now Belongs to an Advertising Company

Google's $2.1 billion acquisition of Fitbit in 2021 placed detailed health data from tens of millions of users — heart rate, sleep patterns, exercise habits, menstrual cycles, stress levels, and blood oxygen measurements — under the control of the world's largest advertising company. Google pledged not to use Fitbit health data for advertising, but the pledge is time-limited, not legally binding in all jurisdictions, and does not prevent Google from using health data for other purposes including product development, AI training, and health-related services.

The Health Data Treasure

Fitbit devices collect some of the most intimate data a technology company can gather. Continuous heart rate monitoring reveals stress levels, emotional states, and cardiovascular health. Sleep tracking documents sleep quality, duration, and disturbances. Activity tracking records exercise habits, sedentary periods, and daily movement patterns. Menstrual cycle tracking, used by millions of Fitbit users, documents reproductive health data. Combined, this data creates a comprehensive health profile that would require extensive medical testing to replicate through traditional healthcare channels.

The Advertising Company Problem

Google's core business is advertising, and the company's history demonstrates a consistent pattern of expanding data collection to improve ad targeting. While current commitments restrict Fitbit health data from direct advertising use, the value of health data for Google's broader AI and services strategy provides ample motivation to find acceptable uses. Health data can inform Google's healthcare initiatives, insurance partnerships, and pharmaceutical advertising without directly using the data for ad targeting — a distinction that satisfies the letter of Google's pledge while potentially violating its spirit.

The post-Dobbs legal landscape has created particular urgency around reproductive health data. Menstrual tracking data stored by Google could theoretically be subpoenaed by law enforcement in jurisdictions where abortion is restricted. Google's data retention policies, law enforcement compliance practices, and the absence of end-to-end encryption for health data create risks that did not exist when users originally entrusted this information to Fitbit as an independent company.

Users concerned about health data privacy should evaluate whether wearable health tracking justifies the data exposure, consider alternatives like Garmin or Whoop that are not owned by advertising companies, and regularly export and delete health data from Google's servers. For users who continue using Fitbit, minimizing the categories of tracked health data reduces the scope of information under Google's control.