Mrs Lisette said because the fitness data is held on your device or app for long periods of time it can make obsessing over it even worse.

“I used to think, well, I did that many steps a month ago so I need to do this many this month,” she said.

BEAT spokesperson Alex Jones told the BBC: “Anybody who has an eating disorder or has recovered from an eating disorder – using a fitness tracker is probably not for you.”

He also thinks there should be more safety features built into health tracking apps, so they do not encourage targets that may be unhealthy for some people.

Those with, or vulnerable to, an eating disorder “can quite often get sucked into calorie counting and setting themselves very stringent targets anyway, so fitness trackers can feed into the same mindset”.