Marmite Roast Potatoes | Slimming Friendly

December 10, 2019
marmite roast potatoes
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These Marmite roast potatoes are so good that even dedicated haters of the kitchen cupboard staple would struggle not to admit that they’re stuff that the very best Sunday dinners are made of. 

With a wonderfully rich colour, they’re fluffy on the inside and deliciously crispy on the outside. 

They’re also slimming friendly, making them a great option for the whole family when you’re trying to eat a little healthier without serving up rabbit food. 

Here’s everything you need to know about making them – they’re super easy, too! 

For the full ingredients list and detailed instructions, see the recipe card at the end of this post. Make sure you check out this important information first though…

How many calories are in this recipe? 

There are 115 calories per serving of these Marmite roast potatoes. 

For reference, an average man needs to consume around 2,500 calories a day to maintain a healthy body weight. For an average woman, it’s around 2,000 calories a day.

Of course, if you’re aiming to lose weight, you’ll want to consume less than this to reach your goals! 

For more information on calories, visit the NHS website

How many Syns are in Marmite roast potatoes? 

If you’re following the Slimming World plan, you’ll be pleased to know that this recipe is entirely Syn free!

What a minute… What even is Marmite?! 

I’m pleased you asked, because even though I’ve been familiar with Marmite for years (after all, it’s a household name, and I think you’d struggle to find someone who hadn’t heard of it), this is something that I found I myself curiously Googling a little while ago. 

It’s quite simply a British food spread made from yeast extract, and a by-product of brewing beer.

When you put it like that, it perhaps doesn’t sound all that appetising. But it’s low in calories, rich in B vitamins, and vegan friendly. And thanks to it being particularly rich in umami – the deliciously savoury, rich taste that’s often found in broths and cooked meats – it’s often used as a flavouring in recipes. 

This, along with its dark colour, makes it perfect for cooking roast potatoes. 

It’s worth noting here that Marmite is NOT gluten free. Due to it being made with wheat, it should be avoided if you have any kind of gluten intolerance. 

How to serve your roast potatoes 

These Marmite roasties are the perfect accompaniment to a Sunday roast with all the trimmings. 

Just make sure that you add plenty of fresh green vegetables to make sure you get enough speed foods! 

Alternatively, they’re a great side dish for my cheese and onion pasties, particularly if you’re vegetarian or just trying to avoid meat. 

slimming world cheese and onion pasties

They’re also ideal with my Syn free steak bakes, as an alternative to chips. 

slimming world steak bakes

Choosing the right ingredients for making these roast potatoes

Do you ever come across a recipe online that you fancy making, only to discover that there’s an ingredients list as long as your arm? 

It’s frustrating, and it can also prove to be really expensive if you have to dash out to the supermarket to buy lots of different things. 

Thankfully though, this recipe requires just three ingredients, and you’ll probably already have at least a couple of them in your kitchen. 

You’ll need: 

If you want to make something extra special and flavoursome, you might want to consider using Marmite XO (extra old).

It’s been matured for 28 days (four times longer than the standard version), and this gives it a richer, more intense flavour.

You’ll find it in Tesco. 

marmite xo

Do you need an Actifry? 

I absolutely love my Actifry, and it’s easily one of the best ever kitchen investments that I’ve ever made. 

If you have one, then I definitely recommend using it when making this recipe. It’ll lead to the best possible results. 

If you don’t own one though, don’t worry. You can still make your roasties! You’ll notice in the recipe card at the bottom of this post, I include instructions for both the Actifry and your oven. 

Looking for more slimming friendly potato recipes? 

Ahh, the humble potato! 

Just because you’re watching your weight or hoping to lose some pounds, it doesn’t mean that you have to give up everyone’s favourite side dish. 

Here are a couple more options that might float your boat… 

the best slimming world chips

These Syn free chips are served up all the time in our house, and they’re super quick and easy. 

slimming world oxo roast potatoes

If you’re a roasties lover, you also need to try these Oxo roast potatoes

I can never decide whether I prefer these or their Marmite counterparts… So both make a regular appearance on my meal plans! 

Marmite Roast Potatoes

These Marmite roasties are a great slimming friendly side dish for your next roast dinner!
Prep Time5 mins
Cook Time35 mins
Course: Side Dish
Cuisine: British
Servings: 4
Calories: 115kcal


  • 4 large potatoes
  • 1 tbsp Marmite
  • Low calorie cooking spray


  • Peel the potatoes and chop into quarters. Rinse in cold water.
  • Place the potatoes in a large saucepan. Pour over boiling water and bring to the boil over a medium to high heat. Allow to simmer for 10 minutes, until starting to soften.
  • Pour the potatoes into a colander, and shake vigorously so the surface of the potatoes become roughed up.

The Actifry Method

  • Put the potatoes in the Actifry, and add the Marmite. Spritz liberally with low calorie cooking spray.
  • Cook in the Actifry for 20-25 minutes, or until crispy on the outside and fluffy on the inside.

The Oven Method

  • Preheat oven to 180 degrees.
  • Place the potatoes into a deep baking dish. Add the Marmite, and gently mix the potatoes with a spoon so they're equally coated as much as possible, being careful not to break them up. Spritz the tops of the potatoes with low calorie cooking spray.
  • Bake in the oven for 40 minutes, or until the potatoes are crispy on the outside and fluffy on the inside.
  • Serve and enjoy!


The nutritional and Syn values provided are carefully calculated and correct at time of publication but may not always be completely accurate.
If you're serious about sticking rigidly to your plan, it's always worth doing your own calculations for extra peace of mind - and remember, we may be using different brands or variations of ingredients which can significantly impact the nutritional and Syn values! is not responsible for any loss or damage due to reliance on nutritional information provided here. is an independent and UNOFFICIAL website, and it is in no way affiliated with, endorsed by, or representative of Slimming World. I’m NOT a Slimming World consultant, nor am I trained to give advice on any aspect of the plan, and so any information provided here should never replace the guidance of your consultant.
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Calories: 115kcal

Have you tried this Marmite roast potatoes recipe? I’d love to see it!

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marmite roast potatoes pin

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