Shalise Tansey

The humble potato chip.

A classic that is easily recognisable by sound alone.

And that's not a fluke.

Food companies put time and money into perfecting the sound of the crunch, all in an effort to bring you back for more.

They're doing it using techniques on addiction, perfected by the tobacco industry.

But it's not just the foods itself.

It's ads like this.

They draw us into buying these products again and again.

Today on The Detail, we look at why we find ultra-processed foods so addictive and how they always seem to end up in our trolleys.

How we're being sucked in by celebrity endorsements, bright colours and something called the health halo effect.

Chips, biscuits, yogurts, protein bars, instant noodles, these are all examples of ultra-processed foods, or UPFs.

They're different from just processed foods.

Senior Research Fellow in Population Health at the University of Auckland, Kelly Garton, explains how.

And the recent research that you came out with is around ultra-processed foods.

Can you tell me a little bit about why you did this research?

What was the new things that you guys had found from this research?

And so what about these foods?

Because I had read your conversation piece and like you'd mentioned, there were feedback loops.

Within these feedback loops, what is it about these foods or UPFs that make it so addictive or want for us to eat more of them?

So, for instance, when we eat a potato chip, what could be in that example to make us want to?