When you the phrase ‘natural flavouring’ on food packaging, just how natural is the process that produces it? What is ‘modified starch’, and why is it such an abundant ingredient in everything we consume? How is it that pita breads can sit in their plastic containers and still be fresh after six months?

These are the questions investigative journalist Joanna Blythman set out to answer in her new book Swallow This: Serving up the food industry’s darkest secrets. She’ll be chatting to Sean Moncrieff today at 3pm, and letting him know exactly what goes into the ingredients we’re ingesting every day.

Tune in live: http://www.newstalk.com/player/

But artificial ingredients aren’t always an unwelcome part of a meal. For doomsday preppers – the kind of people who stockpile enough supplies to survive after a global catastrophe – storing food and water is rarely reliant on the freshest produce.

The photographer Henry Hargreaves has been meeting and documenting the meal plans of these preppers, paying special attention to show diverse locations, religious faiths and dietary requirements - as well as the pressing issue they think will bring about the end of the world as we know it.

Check out the images below:

[All images: Henry Hargreaves]