''It's that notion of sitting on the bank of a river and people keep drowning, so you drag them out and save them, and then someone says, 'why don't you go up the river and see who's pushing them in?''' says Moodie. ''Working in refugee camps was without doubt one of the most instructive parts of my medical training, learning that we should be talking about what's going on in the camps around diets, water and sanitation.''

It's an approach that has guided him through a 35-year career, including in the early days of the HIV/AIDS epidemic when he took a key role in United Nations' efforts to warn communities of the emerging threat. More recently his focus has turned to the diseases caused by smoking, obesity and excessive alcohol consumption.

Obesity and alcohol remain major challenges: ''Whether it's tobacco, alcohol or food, you're fighting major industries who are in a sense the vectors of these industrial epidemics,'' he says.