Best Gluten Free Energy Bars UK: 11 Checked on Their Own Labels
Written by James, founder of Flaming Phoenix and the maker of Phoenix Bars. Updated October 2026.
Eleven energy bars sold in the UK state “gluten free” on the pages I checked, from a 138 kcal Nakd bar to a 557 kcal Phoenix Bar. Which is best depends on how much energy you need and whether you also avoid oats. This page lists all eleven by calories, picks out the oat-free ones, and names the bars that look similar on the shelf but contain gluten.
What “gluten free” means on a UK label
Only food with 20 parts per million of gluten or less can be labelled gluten free in the UK. Oats are the complication. Standard oats are often contaminated with wheat or barley in the field or the mill, so a gluten-free bar has to use oats sold as gluten free. A small number of people who avoid gluten also react to oats themselves, so check whether a bar is oat-based.
How this list was built
I make one of these bars. Every figure and claim comes from the brand’s own UK page, or a major UK supermarket listing where the brand page did not show it, checked on 12 October 2026. I have not taste-tested the other bars. I have only included bars whose page uses the words “gluten free”, and this is not every gluten-free bar on sale in the UK.
The eleven, from most calories to fewest
- Phoenix Bars: 120g, 527 to 557 kcal, 18 to 19g protein. Oat-based. £5.25.
- KMC NRG Bar Kendal Mint Cake: 85g, 342 kcal, almost all sugar. No oats in the main ingredients. £2.49.
- Mountain Fuel Feel Good Bar: 60g, 274 kcal. Oat-based. Out of stock when checked.
- Styrkr BAR50 Date, Almond and Sea Salt: 72g, 273 kcal, about 50g carbohydrate. About £2.50 in a box of 12.
- OTE Anytime Bar Blueberry: 62g, 255 kcal. Oat-based, also nut free.
- Veloforte Di Bosco: 55g, 238 kcal. Fruit and nuts.
- Trek Protein Flapjack: 50g, 227 kcal, 9g protein. Oat-based. £1.85.
- Deliciously Ella oat bar: 50g, about 209 kcal. Oat-based. About £1.
- TRIBE Protein Flapjack: 50g, 200 kcal. Oat-based. Sold out when checked.
- Voom Pocket Rocket Electro Energy: 47g, 176 kcal. No oats in the main ingredients.
- Nakd Cocoa Delight: 35g, 138 kcal. Dates, cashews, raisins and cocoa. About 75p in a four-pack.
All eleven are also stated as vegan or plant-based on the pages I checked. Veloforte Classico is gluten free too, but it contains honey.
If you avoid oats as well
The main ingredients of Nakd, Veloforte Di Bosco, the KMC mint cake bar and Voom Pocket Rocket do not include oats. Read the full ingredients list before you buy, because recipes change. Phoenix Bars, Trek, OTE, Deliciously Ella, TRIBE and Mountain Fuel are all built on gluten-free oats.
Phoenix Bars: Up to 557 Calories Per Bar
Highly compact, low-volume, calorie-dense bars. Soft, easy to eat whole or as a warm porridge. Vegan, gluten-free and contain up to 66g of carbohydrates, 19g of protein & 8 vitamins & minerals.
Look-alikes that are not gluten free
These sit next to the bars above in shops and are easy to pick up by mistake:
- Clif Bar: contains oats and barley malt extract, with a may-contain-wheat warning and no gluten-free claim.
- Torq Explore Flapjack: no gluten-free claim, and not suitable for anyone avoiding gluten cereals.
- Science in Sport Energy Oat Bar: gluten cereals are flagged as an allergen.
- KMC Natural NRG Oat Flapjack: oats flagged as a gluten cereal, unlike the brand’s mint cake bar.
- TRIBE Wildfarmed flapjacks: stated as containing gluten, unlike the TRIBE Protein Flapjack.
- Chia Charge Original Flapjack: no gluten-free claim.
The lesson is that one brand can sell both kinds, so check each bar and each flavour.
Where Phoenix Bars fit
Phoenix Bars are labelled gluten-free and made with gluten-free oats. They are produced in an environment that also handles gluten, and our manufacturer tests production for gluten. Each bar has 527 to 557 kcal, the most of the eleven here and about double most of them, and it can be made into porridge with hot water.
“Being gluten intolerant I can struggle to find fuel so these bars are a game changer for me!” wrote Julie C. in October 2025. “I struggle to find gluten-free nutrition so they were the perfect fuel for my recent 100km ultra marathon,” wrote Alan G. in November 2025. Ned H., a Mountain Leader, wrote in January 2025 that being vegan and gluten free “makes it an ideal emergency snack” when guiding people with dietary requirements.
The trade-offs: at £5.25 it is the dearest bar here, and some people find it dry eaten straight. Alasdair B. gave three stars in July 2026 and called it “too dense and hard to eat when not mixed with water”, while rating it highly as porridge. You can see our high calorie bars on the homepage, and the method in high calorie porridge.
How to choose
- A light snack under £1: Nakd or Deliciously Ella.
- A race bar with the most carbohydrate: Styrkr BAR50.
- A quick sugar hit: the KMC mint cake bar or Voom.
- Avoiding oats too: Nakd, Veloforte Di Bosco, KMC mint cake or Voom.
- The most energy in one bar for a long day: Phoenix Bars.
Common questions
Are oats gluten free? Oats do not contain gluten itself, but standard oats are often contaminated. Only oats sold as gluten free meet the 20 parts per million limit.
Are flapjacks gluten free? Only if they are made with gluten-free oats and labelled that way. See gluten free flapjacks.
Are these bars vegan as well? The eleven listed are stated as vegan or plant-based. For the vegan comparison, see best vegan energy bars UK. For food beyond bars, see high calorie gluten free foods.
Sources: each brand’s UK product page or a UK supermarket listing, checked 12 October 2026. Coeliac UK, the law on gluten free and oats. Flaming Phoenix is not affiliated with any other brand named here. All trademarks belong to their owners.
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