Fries should come in servings of six, professor claims

Next time you're asked if you'd like fries with that, don't be surprised if one of the options is 'six'.

That's the maximum number anyone should eat in a single sitting, a Harvard nutrition professor has claimed.

Eric Rimm told the New York Times potatoes are "starch bombs" made only worse by removing their nutrient-filled skin and frying them in oil.

He's urging people to give up the fries and opt for a salad instead. But if it's fries you want, Dr Rimm says moderation is key.

"There aren't a lot of people who are sending back three-quarters of an order of French fries," Dr Rimm told the paper. "I think it would be nice if your meal came with a side salad and six French fries."

A recent study found people who don't eat fries, or chips as we call them in New Zealand, on average live six months longer than those who indulge and are less likely to have cardiovascular problems and diabetes.

A large McDonald's fries in New Zealand has 1690kj of energy. In the US, where serving sizes are larger, it has 2260kj.

New York-based nutritionist Lisa Moskovitz told the Daily Mail if you can't resist ordering fries, order a smaller kid's meal instead.

"It might not feel so little if you feel you can have it all."

Another nutritionist, Elaine Magee, told the New York Times not all fries are created equal when it comes to health. The best option, she said, would be to make them at home and bake them, or have kumara fries instead.

After those two options, in descending order of healthiness, come chunky, crinkle-cut and shoestring fries. Bringing up the rear are waffle and curly fries, which have a greater surface area and can soak up more oil.