It seems like an unlikely alliance, but Weight Watchers has backed three items on McDonald's menu.

From today, New Zealand McDonald's branches are offering three meals that each add up to 6.5 Weight Watchers' points.

The meals, the Filet-O-Fish, the Chicken McNuggets and the Sweet Chilli Seared Chicken Wrap, are the same meals McDonald's customers are used to. But 9000 staff in 150 restaurants around the country have had training to make the meals more consistently, with the same amount of sauce each time, so they fall within the points system.

The system allows those on the Weight Watchers' programme between 18 and 40 points each day, which they must stay within to obtain and retain their goal weight.

The meals are served with salads and water or diet soft drinks.

Weight Watchers spokesman Chris Stirk said the partnership had been formed after similar alliances with other restaurant chains in the UK and US.

People had a greater chance of losing weight and keeping it off when they did not have to deprive themselves of every indulgence, he said.

McDonald's New Zealand managing director Mark Hawthorne said there were plans to extend the Weight Watchers menu items.

He said the points for each meal had been added up based on the maximum amount of sauce that could be shot out from the company's "sauce guns".

Dr Robyn Toomath, spokeswoman for the Fight the Obesity Epidemic group, said the move would be okay if it convinced existing McDonald's customers to pick a less-fatty food option.

But it was more likely the promotion would simply attract new customers - and thus normalise the regular eating of McDonald's.

On sale:

* Filet-O-Fish, salad and diet drink / water.

* Six chicken nuggets (with sauce), salad and diet drink / water.

* Chicken wrap, medium diet drink / water.

* Total: 6.5 Weight Watchers points.