http://www.ft.com/intl/cms/s/0/b709cf4a-12dd-11e3-a05e-00144feabdc0.html#!

Before Celeste Steenburger takes off on her morning run, she taps the orange button on the MapMyRun app on her iPhone to track the exercise.

The 30-year-old office manager counts calories, logging the food she eats into a separate Lose It! app. When her menstrual cycle begins, she marks the details in the Period Tracker Lite app.

With each bit of health data Ms Steenburger records, third-party companies, some with names she has never heard of, are receiving information about her.

Exclusive research conducted for the Financial Times by Evidon, a web analytics and privacy group, found that the top 20 most visited apps transmit information to a web of nearly 70 companies.

Take MapMyRun, one of the apps Ms Steenburger uses to track her runs. The Evidon study found that 11 separate companies beyond the app’s developer were transmitted data from the app. Those include advertising companies, some of which are subsidiaries of Google, and other digital analytics and tracking groups.

“That does concern me,” Ms Steenburger says. “If I wanted to give my information to those companies I would. This is Big Brother.”

The findings come after an investigation earlier this summer of 43 popular health and fitness apps conducted by advocacy group Privacy Rights Clearinghouse found “considerable privacy risks” not described in the app privacy policies.