What’s the Lowest Calorie Nut? It’s Complicated…

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Helen Foster
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There’s no doubt that nuts are healthy, but, if you’re watching your calories you might be a bit cautious about eating them. Here’s everything you need to know about nuts and calories – including which nut has the lowest calories, which nut might help you cut calories in other ways – and some other useful advice.

If you read this blog often you’ll know that many of the posts on it come about because I’ve wondered something – normally about something I or a friend is eating. This one is no exception!

You see, my name is Helen and I have a problem with Aldi cashew nuts, and. because they taste so sweet it’s got me wondering whether they’re more calorific than the almonds I used to snack on – and whether there’s a less calorific version of both of them.

And so, I decided to investigate and I found out that nuts and calories can be a bit of a complex subject.

Which Nut Has the Lowest Calories?

Okay, gram for gram, the nut with the lowest number of calories per 100g is the chestnut, which, roasted and peeled, has 170 calories per 100g serving.

But, to be fair they aren’t the most common nut that you’re likely to consume – plus they’re pretty dull and dry (which might explain why they’re our winner) and so, here’s how the other, more common nuts, stack up

Lowest Calorie Nuts List

NutCalories per 100g
Brazil Nuts687

If you’re literally here looking for the nuts with the least calories on the label, my work here is done.

However, as I said, when it comes to nuts and calories, it’s a bit more complex than that and there’s a few more things to consider … so, let’s go through a few other facts.

Why Do Nuts Have So Many Calories?

Because they contain quite a lot of fat.

One reason chestnuts have so few calories is that they only have 2.7g of fat per 100g and most of their calories come from carbohydrates instead, compare this to macadamias, one of the highest calorie nuts, which have 77.6g of fat per 100g (and just 4.8g of carbs) and you can understand how much difference that make.

However, before you start shunning nuts because they have fat, most of the fat in nuts is of the healthy unsaturated type though so, they aren’t something you need to cut back on for that reason.


Everything We Thought About Nut Calories is Wrong!

Here’s a fun little fact.

The calculation that determines how many calories are in a food was calculated in a lab looking at how much energy was produced when protein, carbs or fat were burned and assigning a value to this (something called the Atwater Factor).

The calories on the label are then calculated by working out how much fat, protein and carb an individual food contains and multiplying that by these numbers – but, in recent years we’ve discovered our body doesn’t quite work like a laboratory experiment.

The New Way of Thinking

It’s now been discovered that the harder a food is to digest, the less of those calculated calories we might actually absorb.

Rare steak is an example of this – it actually provides ever so slightly fewer calories than well-done steak because we find the fibres in rare meat harder to break down.

And nuts are another example.

In fact, back in 2012 a study by the USDA studied what happened to almonds when actual humans ate them, and realised that, because the fibrous shell around the edge means we don’t absorb all of the fat from the nut (you don’t want to know how they worked that out) they suggested that almonds actually only provide 129 calories per 29g serving (equivalent to 460 calories per 100g).

A 2015 study also showed a similar discrepancy for walnuts – they calculated that 28g of walnuts contained just 146 calories (so 521 calories per 100g).

In 2018, another study revealed a new number for cashews – 137 calories per 28g (489 calories per 100g) – and, guess what happened when they measured pistachios? … They got a number of 538 calories per 100g. All slightly lower than the original Atwater calculation.

Please excuse me while I dance around the house waving flags.

So, Why Aren’t These Numbers on Labels?

Well, in same places they are being used. Kind Bars, for example, readjusted their labelling to use the new numbers, but other companies stick with the Atwater numbers.

So, use the numbers in the table above as a guideline, but, if you start losing more weight than you thought that could be why.

The numbers in our table above also relate to the basic, unprocessed, unmessed with, just came off the tree version of nuts – but, what happens if you add salt, dry roast them, chop them or blanch them… does that make a difference to the calories? Let’s find out…

Do Chopped Nuts Have More Calories?

They don’t contain more calories, but, they might provide slightly more calories because of the reasons we talked about above.

When you chop a food you break it into smaller pieces which your body finds it easier to break down – which means you likely absorb more calories from a chopped nut that if you ate a whole one (especially as most of us don’t chew our food as well as we should).

In one study comparing whole, roasted, chopped almonds – and almond butter, the amount of fat actually absorbed by the body all increased slightly between whole, roasted and chopped almonds (from 53.4% of the fat in whole almonds to 55.6% in chopped ones) – but it went up to an estimated 94% in almond butter.

Meaning you’ll absorb fewer calories from the same number of calories consumed in the form of raw almonds than almond butter!

Do Dry Roasted Nuts Have More Calories?

Today I learned a new thing.

I always thought dry roasted nuts had more calories than other nuts, but actually they seem to have a smidgen less.

According to KP – master makers of nuts – you’ll find 594 calories in 100g of their dry roasted nuts, but 614 calories in the same amount of salted ones!

Turns out dry roasted simply means roasting the nuts with no added oil.

However, as you probably know, dry roasted nuts taste better than plain nuts do (not least because KP add garlic and spice powder to theirs) and so it’s a lot easier to over eat them – and that tiny calorie saving could quickly be negated if you eat more of them because they are yummy.

Oh, and as the experiment above showed you also absorb about 1 per cent more calories from dry roasted nuts than natural ones, although I wouldn’t worry about that too much in the scheme of things!!!

What About Salted Nuts?

Salt itself doesn’t contain calories, but, unsalted nuts that haven’t been processed in any other way, do tend to contain fewer calories than salted versions within the same brand – and the reason is often that some extra oil is used when processing salted nuts.

Like dry roasted nuts, you’re more likely to keep going back for more eating salted nuts over plain ones – and so you could also find yourself consuming more calories for this reason.

Salt also tends to make you thirsty and, unless you’re reaching for water or another no-calorie drink, that’s going to add to your intake.

Which is the Best Nut for Weight Loss?

It’s the pistachio – and not just because they contain the fewest calories.

Pistachios are usually, served in their shells – this means each one takes longer to eat and, you have to consume them one at a time.

This has a marked effect on how many of them people eat – in fact, in one study people at 41% fewer calories when faced with shelled pistachios compared to being given unshelled ones.

And, when you are eating them, pile the shells up in front of you. This was also shown to cut down how many people ate throughout a day as they served as a visual reminder.

Nuts and Calories – The Rules

So, as you can see, the search for the nut with the least number of calories is not quite as simple as you might think, so if you’re eating nuts while counting calories you might want to follow these rules…

Pistachios in their shells will usually lead to the lowest calories consumed for a couple of reasons.

The less messed with a nut is the better. Ideally pick unsalted, whole nuts with their skin on.

The more the nut has added to it, the more moreish it’s going to be! Watch your portion size carefully.

Remember a portion of nuts is only 28g. But as most of us don’t walk around with a set of weighing scales, here’s a rough idea of how many nuts of each type adds up to 28g

How Many Nuts Are in a 28g (1oz) Portion

NutHow Many Can You Eat for 28g
Brazil Nuts6
Pecans12 halves
Walnuts11 halves

So, there you have it. Our guide to nuts and calories. But what if you have other nut questions… here’s some of the other nut related features we’ve covered.

Are activated nuts actually healthier for you. You might have seen these in health food stores and they come with a hefty price tag, so you might be surprised to discover that they may not actually be better for you. Find out why in our guide to activated nuts.

Is Powdered Peanut Butter healthy? We talked above about how you might absorb more calories from nut butters than unprocessed nuts, but powdered peanut butter aims to create the spread you love with fewer calories. See more about it here.

Who is The Wellness Nerd?

My name is Helen Foster, and I’m a health journalist and wellness author. Publications I’ve written for include Women’s Health, Reader’s Digest, Body and Soul, Good Health at the Daily Mail, and more. I have also written 16 books on health and nutrition.

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