What happens when your food choices are determined by nothing but the environment around you and your own resolve? The Food Chain follows the story of 72- year-old grandmother Ann Rodgers, who went missing in the Arizona wilderness in March 2016.

In this illustrated food survival story, we examine the food choices we make when left with just our animal instincts.

The BBC's Emily Thomas uncovers the science behind those decisions too – and what happens to our bodies when our diet goes from balanced to bare with nutritionist Dr Chris Fenn.

(Photo credit: Ann Rodgers)