The Swedish Medicines Agency warns of the growing number of rogue players offering health apps.

Today, there are around half a million health apps, according to the Medical Products Agency - and far from all of them are regulated by legislation that guarantees patient safety.

Namely, only apps that diagnose, prevent, treat or mitigate disease must be CE-marked.

Then it is controlled by an independent party.

Apps that give advice on, for example, diet, exercise, stress management and sleep, do not need to be CE-marked and are not subject to any requirements.

In the worst case, the advice can be downright wrong, says the Medical Products Agency.

Non-serious tests

Unscientific health advice also abounds on social media and in books and magazines.

- Many people are interested in health and there are great opportunities for the players to sell everything from nutritional supplements, tests and exercise programs.

There is a lot of fluff in the health industry, says Jessica Norrbom, molecular biologist and researcher at the Karolinska Institutet in Solna.

She is also co-author of the books "Frisk utan flum" and "Frisk utan fusk".

She also sees certain risks with anyone being able to give health advice on, for example, social media or via an app.

Some of the players also sell expensive health tests, you can measure your hormones or gut bacteria, among other things.

- But today we don't know exactly what a bacterial flora in the gut should look like, so no one really knows how the test should be interpreted and what that interpretation means in that case, says Jessica Norrbom.

More exercise

For those interested in health, it can be difficult to distinguish fake health advice from those based on science.

And the evidence-based advice is easy to follow:

- It's enough to move a little more, all movement counts.

When it comes to the diet, one can add healthy things rather than banning certain foods completely.

Another tip is to prioritize your sleep.

Here, Jesscia Norrbom tells you how to uncover false health advice and where to find reliable information.