You're about to listen to a BBC podcast and maybe it's when I had a hand in.

I'm Tammy Walker and I produce podcasts for the BBC.

My role is to give new and diverse creators a voice with the opportunity to build a career.

That's the thing I love about podcasts.

You start with just a good idea, but then you have the space to see where it goes.

And doing that at the BBC means we can really run with the best stories

while developing the most unique audio talent.

So if you like what you hear, why not check out the huge range of podcast we've got on BBC

Sounds.

The first two days are difficult, your head hurts or your joints hurt or something is uncomfortable.

You get used to it and amazingly enough, the second or third day you have this energy in you.

Welcome to Crowd Science from the BBC World Service.

I'm Marnie Chesterton.

You know, you have a little camarader.

Like a little fraternity.

And welcome to a clinic on the Swiss German border,

where the sun's shining, the birds are chirping.

You have like a high.

Everything seems to be very new again.

But despite that talk of a high, nobody's on drugs. In fact, these people aren't on anything. I've come to one of the few places in the world

where you can pay a lot of money to not eat. Because on this week's program, we're going

to investigate why anyone would do this

...