"Choosing a healthier diet has to be made easier, because good eating habits are one of the best and most cost-effective ways to prevent disease," she said.
Dr Eyles, 34, was raised in Wanganui and studied at Otago University before moving to Auckland to work at the National Institute for Health Innovation and complete a doctorate in nutrition and healthy eating.
She is married to world champion K1 kayaker Ben Fouhy and is a keen runner.
The framework for the app was developed by the George Institute for Global Health in Australia and the Australian version has so far been downloaded 400,000 times.
Dr Eyles had helped make the app specific to New Zealand and was pleased with the result - "as a researcher things can get frustrating but this is a real win.
"It's really good, and it's nice to be passionate about what you do and I've always been passionate about food and nutrition."
She is currently working on a study to reduce saturated fats and sodium from processed foods and will also continue to work on Foodswitch and improve the app's database of 8500 different foods.
So far more than 1500 extra foods had been suggested by users of the app.