Low-carb potatoes: legit or marketing?

I first came across low-carb potatoes at a potluck. I was confused – weren’t potatoes nearly entirely comprised of carbohydrates?

It turns out there’s more to a potato than carbohydrates. You'll find a nutritious cocktail of vitamins C and B6, as well as potassium, folate, magnesium and fibre.

How many carbs are in the average potato?

Potatoes marketed as “low carb” are a waxy variety, so we compared them with average waxy potatoes to see if there’s any difference in nutrition and price.

We checked the Food Composition Database, a resource run by Plant and Food Research and the Ministry of Health that provides accurate nutritional information on various foods.

The database lists 10.8g of carbohydrates per 100g serving of waxy potatoes, boiled with skin on and no salt added. That’s the same as Lotatoes low-carb potatoes and 0.3g of carbohydrates less than Sunlite low-carb potatoes (see table below).

A Plant and Food Research spokesperson said the average waxy potatoes “were purchased from various supermarkets around the country”. They were from bags labelled for boiling and were a mix of Nadine and Draga varieties, mostly Nadine, as the variety was more commonly available in supermarkets. A Woolworths spokesperson confirmed that most of its boiling potatoes were the Nadine variety.

When we checked, a kilogram of potatoes labelled for boiling was, on average, cheaper than a kilogram of low-carb potatoes.

Low-carb potatoes compared

Lotatoes by T&G Global

T&G’s website claimed Lotatoes had 10.8g of carbohydrates per 100g serving.

According to the packet, that’s 40% less carbohydrates than Agria potatoes. But on its website, it compared the carb content to both Agria and Rua varieties.

When we asked T&G to substantiate its claims, it said:

“As the Rua variety will soon no longer be readily available in New Zealand, we have ceased using it as part of our comparison and have recently removed the reference to the variety on our packaging.”

Following our query, it removed reference to the Rua Variety from its website.

When we asked to see the data the Agria claim was based on, T&G refused, citing commercial sensitivities. Listings across the web for Agria potatoes show the variety contains around 15g of carbohydrates per 100g serving.

T&G used to refer to the Food Composition Database for its data on carbohydrates in potatoes. It said it no longer used the database because the nutritional information recently changed to reflect the composition of potatoes generally, rather than individual varieties. T&G now test the potatoes annually through AsureQuality, “an independent and Government owned lab.”

Sunlite low-carb potatoes by Gropak

Gropak claims its low-carb Sunlite potatoes contain 11.1g of carbohydrates per 100g serving, which it says is at least 25% less than the common NZ Rua potato per serving.

We asked if it could substantiate that claim, but Gropak just repeated the information on its website: “This claim is a Food Standards Australia / New Zealand Guideline, that when making a low-carb claim – all potatoes must be at least 25% less carbs than the NZ Rua Potato. As per our website, we test each new production site prior to packing, by sending a sample to Massey University Nutritional Lab for Carb level testing.”

While T&G said the Rua variety would not be readily available soon, Gropak said the potatoes were just out of season. A quick Google search at the time of publishing shows that Rua potatoes aren’t currently available in supermarkets.

How does a low-carb potato taste?

I bought a bag of Lotatoes to compare their taste to that of a standard supermarket potato. I boiled, baked, mashed, and boiled then fried to see how they stacked up.

I chopped the potatoes for mashing into 2cm dice while I cut the boiling potatoes in half. I put the potatoes for baking whole into the oven and sliced a couple of big potatoes into thick planks for the fries. When chopping the potatoes, I noticed a lot of liquid coming out – a sign of things to come.

The mash was the most successful preparation. With some butter and salt, it was nearly indistinguishable from your average spud.

Both the boiled and baked Lotatoes had a slightly watery texture. T&G said Lotatoes had a low dry-matter content, which could explain this.

Despite T&G warning Lotatoes might not be so good fried, I was pleasantly surprised with the results. They lacked a bit of crispness, but overall held up well to a deep fry. The bigger catch was, again, the watery texture.

Why would someone choose low carb?

Sylvia North, a registered dietician at Fearless Nutrition, said there were a few reasons.

“The increase in low-carb products certainly reflects a cultural trend in eating patterns as a whole,” she said.

Importantly, low-carb options can be better for some health conditions. According to Sylvia, “Carbohydrate restriction is an effective way to improve the metabolic markers in someone with insulin resistance - especially for people with pre-diabetes or type 2 diabetes.”

But Sylvia warned that just because a product is low in carbohydrates doesn’t mean it’s a healthier choice.

“The most significant challenge we have in public health nutrition is the influence of the food industry in driving the consumption of ultra-processed foods. Ultra-processed foods, even if they're low carb, are not ideal, at best, and, at worst, damaging to human health.”

Our verdict: Save money and stick with a standard waxy spud

You don’t need to buy potatoes marketed as “low carb” to reduce your carb intake – your standard waxy supermarket spud will do. Their carbohydrate content is likely pretty similar to that of a “low-carb” potato – in some cases, even lower than that claimed for a low-carb potato. These potatoes are also likely to be cheaper than a speciality low-carb variety.

If you prefer a high-starch, floury Agria over waxy potatoes, the Lotatoes and Sunlite products have lower carbs in comparison. But Sylvia said the difference in carbs between a low-carb potato and an Agria potato isn’t a lot. “The carb difference isn't drastic. People who want to keep a larger portion of potato on their plate for less carbs may like them,” Sylvia said.

“Otherwise, if you're limiting carbs, of course, you can also just have a smaller portion of a regular potato and just increase the quantity of other vegetables.”