Protein bars: Important supplement or waste of money?

I’M a big fan of protein bars: to munch on during the day, to have after a workout or even to enjoy warmed up with a bit of Greek yoghurt.

I’m clearly not alone in my fondness for them, because the protein bar market has exploded in recent years. Are they really all that special though? That’s what I’ll set out to explore in this piece.

First of all, I’ve got two key points to make:

  1. Just because something has 'protein' in the name doesn’t mean it’s healthy or any better for you than a standard snack bar - or worth the calories and price-tag for that matter.
  2. We shouldn’t rely on bars to hit our daily protein intake and they shouldn't be a meal replacement. Protein bars are a supplement to aid our goals, particularly if we're in a rush and need a healthier snack option to chocolate bars.


A lot of so called ‘high protein’ foods actually contain very little protein per serving size, or a minimal amount more compared to the standard product. A perfect example would be ‘Protein Weetabix'. Normal Weetabix contains 4.6g of protein per serving and ‘Protein’ Weetabix' contains 7.6g per serving: not exactly worthy of the protein title.

Since Areta et al. 9 (3) in 2013, the consensus is that the optimal feeding strategy for increased protein synthesis is a pulsing strategy, whereby you consume 20-25g (0.3g/kg BM) every three hours after resistance training.

So it stands to reason that if you’re aiming to increase your muscle mass and/or recover post resistance training, then choosing a bar which contains 20g protein would be the wisest option. Protein bars marketed to athletes tend to contain 20g or more of protein for this exact reason. However, other more commercial bars often fall short of this optimal amount. Is it worth the calories if you’re not getting the gains?


Depending on the ingredients and macro content, some protein bars aren’t much better than a regular chocolate or cereal bar. Take the new Yorkie Protein Crisp Bar - with the macros and ingredients of this ‘protein’ bar, you may as well just eat a regular Yorkie.

Protein bars made in America – BPI, Quest, Optimum Nutrition - will display carbohydrates as NET Carbs. That is essentially the amount of carbohydrate that will be digested by the body. Some UK bars, such as Grenade & PhD Smart, display Impact Carbs, which is basically the same thing.

Protein bars with low NET or Impact carbs can be effective for those on low carbohydrate diets as they do not affect blood glucose levels in the same way as normal sugars.


Sugar alcohols, or polyols, enable these bars to be low calorie but high taste. Polyols are sweet but are not fully absorbed by the body, meaning they provide a lot less calories per gram than sugar. However, they are still a carbohydrate, so will be listed as a carb on the nutritional information. Commonly used polyols include:

  • Erythritol: 0kcal
  • Mannitol: 1.6kcal
  • Sorbitol: 2.6kcal
  • Maltitol: 2.1kcal

In addition to having fewer calories per gram, polyols are beneficial to diabetics because they do not cause sudden blood glucose spikes – and they don’t contribute to tooth decay.

As we said above, polyols are low in calories because they are not completely digested by the small intestine. The non-digested parts are transported to the large intestine, where they are fermented. As a result of the fermentation, the body produces gases. These can cause bloating and flatulence.

Water also follows the non-digested polyols in the large intestine. Any water which is not re-absorbed by the body softens faeces and can cause laxative effects. The effects of polyols on the stomach are largely individualised, and some people are able to handle more than others, but it is not recommended to consume more than 25g per day.

That means one protein bar per day is fine, but two may be pushing it. As of yet, there is no research to suggest that polyols cause any detrimental long-term health effects.


If you’re a professional or sponsored athlete governed by UKAD rules and regulations, then you will need to check that your protein bar has been drug tested through Informed Sport. You can do this by looking for the batch number on the Informed Sport website or by checking for an Informed Sport logo on the bar.


I've done a little product test of some well-known protein bars, which you can see below. My personal favourite is the Grenade Dark Chocolate Mint: it’s Informed Sport tested, has a great texture and there are loads of delicious flavours.

However, the Fulfil Triple Chocolate Deluxe bar and PhD Diet Whey Salted Caramel come a close second, with the only thing letting them down being the slightly hard textures.

In summary, the things to look out for with you bar are:

  • Total protein: Does it contain 20g protein?
  • Carbohydrates: Are they impact carbohydrates? Or Sugar Alcohols?
  • Sugars: Is there a lot of added sugar in there to make it taste better?
  • Could you get the same benefit from real food?
  • Do you need it to be drug tested?

This piece originally appeared on the FSCR website. I offer individualised nutrition programmes, so if you would like to get in touch, please contact me on

Laura Andrews is the Lead Performance Nutritionist at Arsenal. She previously worked for QPR for almost six years.

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