Apple changed its privacy rules to ensure the increasing number of health and fitness apps are not hindered by concerns about how developers use personal data.

A Financial Times report said the rules will stop personal data collected via Apple’s HealthKit platform being used to target users with adverts for products such as weight loss remedies.

The HealthKit API will be introduced as part of the forthcoming iOS8 update, to provide “a single place that applications contribute to a composite profile of your activity and health”. It is likely the introduction will coincide with Apple’s introduction of a wearable device.

Along with the API, Apple’s Health app monitors health data, such as calories and sleep patterns, and can be integrated with third party apps such as the Nike+ fitness app.

The latest update to the iOS developer program licence agreement includes a provision whereby developers must “not sell an end-user’s health information collected through the HealthKit API to advertising platforms, data brokers or information resellers”.

Developers wanting to make use of the HealthKit technology must also commit to the set of rules, including linking to a privacy policy.

Apple’s approach differs from Google which relies on targeted ads for a large part of its revenue.

Regulators and privacy groups have found that some developers pass on user data to advertising networks, often without the users’ knowledge.

Apple is being particularly careful around health-related apps, and discussed what it called ‘medical applications’ with the US Food and Drug Administration at the beginning of the year, according to the Financial Times report.