There are plenty of flavours to choose from, some with an extra dose of fibre, but the texture may divide opinion.

Optimum Nutrition Protein Bar


From £2.75 per bar or £24.99 for 10 bars (not yet available in the US),


  • Low in sugar
  • Contains a good amount of protein
  • Lowest amount of polyols on test


  • Sweet tasting
  • Claggy mouth feel
  • Slightly gritty texture

Taste: 3/5
Health: 4/5
Protein: 5/5
OVERALL: 3.5/5

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Optimum Nutrition’s range of protein bars has 11 flavours, including three vegan options. Their protein blend is made up of whey protein isolate and calcium caseinate and like most protein bars they contain soy.

Optimum Nutrition Protein Bar benefits

Each flavour hits the magic 20g protein mark, making it a useful post-workout option. It’s a good source of fibre, too, with up to 12g per 60g serving depending on the flavour.

Optimum Nutrition bars are fairly low in sugar, with 2g per serving. It’s the highest amount of any bars on test, although the difference is marginal. They are sweetened with sorbitol, erythritol and sucralose (polyols). Yet they only contain 12g polyols, less than other bars in the category.

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We tried the chocolate caramel whipped bar, which is covered in milk chocolate with a crisp centre and a caramel filling. It’s not chewy like other bars because there’s no collagen hydrolysate in the protein mix.

The taste and texture of protein bars can often be a matter of personal preference. We struggled a bit with the chocolate caramel whipped bar. It tastes very sweet and the crunchy texture is followed by a slight grittiness. It also has a claggy mouth feel which makes it quite hard to enjoy.

However, other varieties such as the Crunch and vegan versions may have a different texture that’s more up your street.

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If the texture isn’t an issue for you, you’ll get a decent protein dose as well as a fibre fix with most flavours. However, if that’s make or break for you, or you don’t like overly sweet protein snacks, then you might need to look elsewhere.