Why Does My Protein Bar Taste Artificial? Ingredients to Avoid

If your protein bar tastes artificial or leaves you bloated, the ingredient list usually tells you why. Seven of the nine Myprotein and Bulk bars we checked replace sugar with maltitol, two add sucralose, and most keep themselves soft with glycerol. This guide explains what each of those ingredients does, which ones are linked to aftertaste or bloating, and which Myprotein, Protein Works and Bulk bars avoid them. We read every Myprotein and Bulk ingredient list on the brand's own website on 3 October 2026; for Protein Works we could only use the claims in its product descriptions. For prices and the overall ranking, see the best protein bars in the UK.

Why does my protein bar taste so artificial?

The artificial taste usually comes from the sugar replacements: seven of the nine Myprotein and Bulk bars we checked use maltitol, and the Myprotein Layered Bar in Gingerbread uses three sweeteners, maltitol, isomalt and sucralose, checked 3 October 2026. Bulk Hero pairs maltitol with sucralose. Intense sweeteners are used in tiny amounts and can leave an aftertaste. For acesulfame K the mechanism is known: Kuhn et al., 2004 showed that acesulfame K and saccharin activate two human bitter taste receptors, TAS2R43 and TAS2R44, at concentrations known to taste bitter. None of the bars in this guide lists either one.

The rest is texture. Bars replace the bulk of sugar with glycerol (listed as a humectant, which keeps the bar soft), maltitol and fibres such as chicory root fibre and oligofructose, so the bar is built from different ingredients to a chocolate bar even when it looks like one. Protein bars are also prone to going hard as they age: in Zhou et al., 2013, Maillard reactions between protein and reducing sugars hardened model protein bars in storage, and replacing those sugars with sugar alcohols kept the texture steadier, which helps explain why sugar alcohols are so common in bars.

Read from each ingredient list on myprotein.com, bulk.com and theproteinworks.com on 3 October 2026 (Big Little Bar: Chocolate Brownie Boogie and Chocolate Hazelnut Honcho). *Protein Works' own claims from its product description; we couldn't read the Ridiculous Vegan Bar's ingredient list. “Seed oil” means a refined oil such as sunflower or rapeseed oil; lecithin emulsifiers are not counted. “Polyols declared” is the figure on the nutrition panel, where the brand gives one. Gelatin is made from collagen.

Which protein bars have no artificial sweeteners?

Two Myprotein bars we checked have no sweetener of any kind: the Crispy Protein Wafer in Chocolate, with 15g of protein in 195 kcal sweetened by sugar and fructose, and the Layered Bar in Hotel Chocolat Salted Caramel, with 18g of protein in 236 kcal, checked 3 October 2026. The cost is sugar: 5.5g and 6.8g per bar, against 1.9g in the maltitol-sweetened Layered Bar in Triple Chocolate Fudge. Protein Works says its Ridiculous Vegan Protein Bar uses “only natural sweeteners”, though its product description doesn't say which.

No maltitol, no sucralose, no palm oil

Myprotein Layered Protein Bar

The Layered Bar made with Hotel Chocolat, built on corn fibre, milk protein and 72% couverture chocolate rather than maltitol. £20.49 for 12 on myprotein.com, checked 3 October 2026.

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The Layered Bar made with Hotel Chocolat, built on corn fibre, milk protein and 72% couverture chocolate rather than maltitol. £20.49 for 12 on myprotein.com, checked 3 October 2026.

Pros

• + No maltitol or intense sweetener in the ingredient list
• + No palm oil
• + 18g protein in 236 kcal

Cons

• – 6.8g of sugar per bar, more than three times the Triple Chocolate Fudge flavour
• – Contains hydrolysed bovine collagen
• – £1.71 a bar, against £1.62 for most Layered flavours

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Most other Myprotein bars skip intense sweeteners but use maltitol: the Layered Bar in Triple Chocolate Fudge, every Impact Bar flavour we read and the Soft Protein Bar list maltitol as their only sweetener. Maltitol is a polyol rather than an intense sweetener; the WHO's 2023 guideline on non-sugar sweeteners explicitly leaves polyols out because they contain calories. Sucralose (E955) is an approved food additive in the UK, so avoiding it is a matter of taste and preference rather than safety. The same logic applies to powders, which we cover in protein powder without artificial sweeteners.

No sweeteners at all

Myprotein Crispy Protein Wafer

A chocolate-filled wafer with a dark chocolate coating and a milk protein and beef gelatine blend. £16.49 for 10 on myprotein.com, checked 3 October 2026.

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A chocolate-filled wafer with a dark chocolate coating and a milk protein and beef gelatine blend. £16.49 for 10 on myprotein.com, checked 3 October 2026.

Pros

• + Sweetened with sugar and fructose only: no maltitol, no sucralose
• + 15g protein in 195 kcal
• + Rated 4.8 out of 5 from 1,640 reviews on myprotein.com

Cons

• – 5.5g of sugar per wafer
• – 6.0g of saturated fat, 30% of the NHS daily limit for women
• – Uses palm oil, and hydrolysed beef gelatine is in the protein blend

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Which protein bars are free from sucralose and maltitol?

Two of the bars we checked are free from both: the Myprotein Crispy Protein Wafer in Chocolate (15g of protein, 195 kcal) and the Myprotein Layered Bar in Hotel Chocolat Salted Caramel (18g of protein, 236 kcal), checked 3 October 2026. Every Myprotein and Bulk bar we checked with 16g of protein or more uses maltitol, apart from that Hotel Chocolat Layered flavour. Check each flavour, because the recipe changes within one bar: the Layered Bar in Triple Chocolate Fudge has no sucralose, but Gingerbread, White Gold and Strawberry all list it.

Bulk Hero uses both maltitol and sucralose, and so does the Layered Bar in Gingerbread, which adds isomalt, another polyol, in its white chocolate flavour coating.

Why do protein bars make me bloated?

Polyols are the most common reason: Bulk Hero Protein Bar lists 13g of polyols in a 50g bar, or 26g per 100g, checked 3 October 2026, and polyols are only partly absorbed, so the rest is fermented in the gut. A systematic review of 79 studies (Lenhart and Chey, 2017) found polyols cause dose-dependent flatulence, abdominal discomfort and laxative effects in both healthy people and people with IBS. That is why UK food labelling law, Annex III of Regulation 1169/2011, makes any food with more than 10% added polyols carry the words “excessive consumption may produce laxative effects”. Bulk prints it on the Hero bar, and Myprotein prints it on the Layered Triple Chocolate Fudge and Impact pages.

The dose is what matters. In a double-blind trial in 20 young adults, Storey et al., 1998 found 30g of maltitol in chocolate caused no significant symptoms, while 40g caused mild rumbling and wind, though not more laxation. In Ruskoné-Fourmestraux et al., 2003, diarrhoea appeared only at very high daily doses, around 92g of maltitol on average. Bulk suggests one or two Hero bars a day, which adds up to 26g of polyols, and that figure includes glycerol, which counts as a polyol under the UK definition, so not all of it is maltitol. The Myprotein Layered Bar in Gingerbread declares 5.0g of polyols per bar. One bar is unlikely to trouble most people; two or three in a day might.

Added fibres are the second cause. In Bonnema et al., 2010, 10g of oligofructose substantially increased gut symptoms, mostly wind and then bloating, while up to 5g of oligofructose and 10g of native inulin were well tolerated. Oligofructose is in most Myprotein Layered flavours, every Impact flavour we read, the Soft Protein Bar and Bulk Hero, and the Layered Triple Chocolate Fudge and Peanut Butter Protein Bar add chicory root fibre. The Impact Bar in Fudge Brownie lists oligofructose second and has 8.6g of fibre per bar. Polydextrose, used in Bulk Hero and the Soft Protein Bar, is gentler: a review of nine tolerance studies (Flood et al., 2004) found it better tolerated than polyols, with a laxative threshold of about 50g in a single dose. If whey shakes bloat you too, the cause there is more often lactose, which our best protein powder for sensitive stomachs guide covers.

How do you read a protein bar label?

Read the ingredient list for eight ingredients: sucralose, maltitol (and other polyols such as isomalt), glycerol, polydextrose, isomalto-oligosaccharides, chicory fibre or oligofructose, collagen or gelatin, and the fat source. On the nutrition panel, check the polyols line, because UK rules exclude polyols from “sugars”: Bulk Hero shows 1.4g of sugar and 13g of polyols on the same panel, checked 3 October 2026. Polyols also carry fewer calories, 2.4 kcal per gram against 4 for other carbohydrates, under Annex XIV of Regulation 1169/2011.

Ingredient lists read on myprotein.com and bulk.com on 3 October 2026; Protein Works entries are its own claims. The Myprotein Layered Bar in Gingerbread lists isomalto-oligosaccharides second, labelled “a source of glucose”, and White Gold and Strawberry list them first. The IMO study, Gourineni et al., 2018, was written by employees of an IMO supplier.

Does collagen or gelatin make a protein bar worse?

Collagen and gelatin lower the quality of a bar's protein rather than its taste: collagen protein lacks tryptophan, one of the indispensable amino acids, so it is classed as an incomplete protein (Paul et al., 2019), and gelatin is made from collagen. Hydrolysed beef gelatin is the fourth ingredient in the Myprotein Layered Bar in Triple Chocolate Fudge, and Bulk Hero's protein blend includes hydrolysed bovine collagen, checked 3 October 2026. Neither brand says how much of the protein figure it supplies.

In practice the effect is small if the rest of your diet carries complete protein, and the same paper calculated that collagen could make up as much as 36% of daily protein while still meeting indispensable amino acid needs. It does mean a 20g bar with gelatin is not the same as 20g of whey. If you want to avoid it, the Myprotein Impact Bar in Fudge Brownie, the Soft Protein Bar and the Peanut Butter Protein Bar list none, and the plant-based Protein Works Ridiculous Vegan Bar can't contain any. If you want collagen for its own sake, see the best collagen UK guide.

Are there any protein bars without palm oil?

Yes: the Myprotein Impact Bar in Fudge Brownie uses shea fat, cocoa butter and rapeseed oil instead, the Myprotein Layered Bar in Hotel Chocolat Salted Caramel has no palm oil in its list, and Protein Works says its Ridiculous Vegan Protein Bar is “purposefully palm oil free”, checked 3 October 2026. The other Myprotein bars we read and Bulk Hero use palm oil or palm kernel oil, and it changes by flavour: the Impact Bar in Caramel Nut has both.

No palm oil, no gelatin, no sucralose

Myprotein Impact Protein Bar

Myprotein's triple-layer caramel bar in its palm-free Fudge Brownie recipe: 20g of protein in 233 kcal, marked suitable for vegetarians. £19.49 for 12 on myprotein.com, checked 3 October 2026.

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Myprotein's triple-layer caramel bar in its palm-free Fudge Brownie recipe: 20g of protein in 233 kcal, marked suitable for vegetarians. £19.49 for 12 on myprotein.com, checked 3 October 2026.

Pros

• + No palm oil: shea fat, cocoa butter and rapeseed oil instead
• + No gelatin or collagen in the Fudge Brownie recipe
• + 20g protein with 1.9g sugar

Cons

• – Maltitol is the first ingredient
• – Oligofructose second, with 8.6g of fibre per bar, which may not suit a sensitive gut
• – Other Impact flavours do use palm oil and beef gelatin

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The nutrition reason people give for avoiding palm oil is saturated fat. The NHS lists palm oil, coconut oil and chocolate confectionery among foods high in saturated fat, and sets daily limits of 30g for men and 20g for women. The palm-free Impact Fudge Brownie still has 3.8g of saturated fat, because cocoa butter, shea and milk add it too, while the Crispy Protein Wafer, with palm oil, has 6.0g. Others avoid palm oil for environmental reasons, which is a values choice rather than a nutrition one.

Palm oil free and plant based

Protein Works Ridiculous Vegan Protein Bar

Protein Works' vegan bar: biscuit dough, nuts and caramel in plant-based chocolate. Protein Works says it has 15g of protein in under 200 kcal. From £11.99 for 9 on theproteinworks.com, checked 3 October 2026.

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Protein Works' vegan bar: biscuit dough, nuts and caramel in plant-based chocolate. Protein Works says it has 15g of protein in under 200 kcal. From £11.99 for 9 on theproteinworks.com, checked 3 October 2026.

Pros

• + Purposefully palm oil free, according to Protein Works
• + Only natural sweeteners and no artificial flavours or colours, according to Protein Works
• + 15g of plant protein, so no collagen or gelatin

Cons

• – Protein Works doesn't name the sweeteners or publish a full panel in its product description
• – We couldn't read its ingredient list ourselves

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Are there protein bars made without seed oils, and does it matter?

Only one of the Myprotein and Bulk bars we checked uses no seed oil: the Myprotein Peanut Butter Protein Bar, made with shea, coconut, palm and palm kernel oils, which has just 8.0g of protein, checked 3 October 2026. Every other bar uses rapeseed or sunflower oil, including the palm-free Impact Fudge Brownie and Hotel Chocolat Layered Bar. Notice the trade-off: the one bar without seed oil swaps it for palm and coconut fat, both of which the NHS lists as high in saturated fat, and it carries 4.9g per 38g bar. Protein Works doesn't say which oils its bars use.

The evidence doesn't back the seed oil scare. A systematic review of 15 randomised controlled trials (Johnson and Fritsche, 2012) found virtually no evidence that adding linoleic acid, the omega-6 fat behind the seed oil worry, raises inflammatory markers such as C-reactive protein in healthy people. The NHS advises replacing saturated fats with unsaturated ones and names rapeseed, corn and sunflower oils as sources of polyunsaturated fat. A bar with a little rapeseed oil is not a reason for concern.

Which bar should you buy if you want a cleaner label?

Buy the Myprotein Layered Bar in Hotel Chocolat Salted Caramel if you want no maltitol, no intense sweetener and no palm oil: 18g of protein in 236 kcal for £1.71 a bar, checked 3 October 2026, with 6.8g of sugar as the trade-off. Buy the Myprotein Impact Bar in Fudge Brownie if maltitol doesn't bother you but you want no sucralose, no palm oil and no gelatin. Buy the Protein Works Ridiculous Vegan Protein Bar if you're vegan.

Skip the clean-label route if calories matter more than the ingredient list: Protein Works The Big Little Bar gives 10g of protein in 105 kcal with 0.9g of sugar, sweetened with maltitol but with no sucralose and no palm oil, and Bulk Hero gives 15g of protein in 175 kcal at the cost of sucralose, palm oil and 13g of polyols. For the full ranking with prices, read the best protein bars in the UK, and for clean-label powders, see the cleanest protein powder UK guide.

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