Why Sarah Wilson lives out of a backpack at Airbnb homes despite being worth millions.

Sarah Wilson has built a multi-million dollar I Quit Sugar empire, but despite all her wealth, lives from a backpack with no fixed address.

“I’ve always been very minimalist… I’ve lived out of one suitcase now for seven years now and I’ve had no fixed address,” she told Mamamia’s Can’t Live Without host Mel Buttle during a podcast interview in July 2016.

“So I move where I want to be… and I just take the one suitcase of belongings.”

Wilson said the transition from minimal possessions to very minimal possessions was sparked when she developed auto-immune disease Hashimotos in 2007.

Her diagnosis prompted her to move to an old Army shed in Byron Bay for a year and a half, while she recovered and wrote I Quit Sugar.

The former Cosmo magazine editor, who has previously opened up about her battle with anxiety, told The Sydney Morning Herald this week she's found "letting go" to be very beneficial.

"I've let go of a lot of things. I've let go of possessions, I've let go of how a 43-year-old woman should be living," she told the publication.

In her book, First, We Make the Beast Beautiful, Wilson shares how she went from clutching at external things to deal with her feeling of anxiety, to learning to sit with - and actually find the beauty in - her internal discomfort.

Listen: Sarah Wilson talks about why she can’t live without zucchinis and that her diet doesn’t actually involve quitting sugar.

"I've dived off into nothingness many times – I've let go of a job, I've let go of Cosmo or Masterchef or whatever it is – and I've dived into the unknown and every time I've been caught and landed somewhere better but people are so scared to do it because we fear the unknown, and that's got a lot to do with letting go, we don't know what's going to happen when we release our fingers."

Wilson said she's found that if she ever feels the urge to try to hold onto things, it's because "things start to feel a bit shit" and takes it as a sign she should do the opposite.

"I'm not mindful of my letting go-ness all the time – it's only when things start to feel a bit shit that I start to pull back a bit. I reach out and grip – that's the best reminder for letting go and softening and pulling back."