The Counties Manukau District Health Board and McDonalds have been testing whether customers in the area's 21 outlets were happy to substitute Sprite, which has a high sugar content, for Sprite Zero, which contains artificial sweeteners.

The move amounts to a 17 percent reduction in sugar intake.

Chairman Pat Sneddon says the trial has been a huge success and the DHB wants to extend it to other drink brands sold at McDonalds.

He says the scheme is linked with the DHB's Lets Beat Diabetes Programme.

McDonald's spokeswoman Jo Redfern Hardisty says the restaurant chain is also considering extending the trial beyond Counties Manukau's borders.