Are Protein Bars Actually Healthy? The Truth About Sugar Alcohols & Fillers

Protein bars have become a go-to snack for anyone looking for something convenient, filling and high in protein. Walk down the snack aisle and you'll find bars promising 15 or 20 grams of protein, low sugar, high fibre, no added sugar and plenty of other benefits that can make them seem like an obvious healthier choice. 

But what you find on the back of the packet can be quite different from what the front suggests. Some protein bars have relatively simple ingredient lists, while others contain sugar alcohols, added fibres, syrups, gums, emulsifiers, sweeteners and other ingredients you may not immediately recognise. 

So, are protein bars actually healthy?

The answer isn't as simple as yes or no. Rather than judging a protein bar by a single ingredient or marketing claim, it makes more sense to look at the whole product—its protein, sugar, fibre, fats, serving size and ingredients, as well as what you actually want from your snack.

In this guide, we'll break down what to look for on a protein bar label, explain what sugar alcohols and so-called "fillers" actually do, and help you make a more informed choice the next time you're standing in front of the protein bar aisle.

First: Are protein bars actually healthy?

The short answer is: they can be. But simply being called a "protein bar" doesn't automatically make a product a healthy choice.

Protein bars vary considerably in their ingredients and nutritional profile. Some provide a substantial amount of protein alongside fibre, nuts, seeds and other nutrient-dense ingredients. Others may be higher in added sugars, saturated fat or kilojoules, despite having plenty of protein.

That's why it's helpful to think of "protein bar" as a type of food rather than a measure of how healthy something is. Just as breakfast cereals, yoghurts or muesli bars can differ significantly from one product to another, so can protein bars.

They can certainly have a useful place in a balanced diet. Protein bars offer a portable and convenient source of protein, which can be particularly handy when you're travelling, at work, after exercise or simply don't have easy access to a protein-rich meal or snack.

Rather than judging a bar by its protein content alone, consider the overall nutritional picture, including:

• Protein: How much does one bar actually provide?

• Sugar: How much sugar does it contain, and where is it coming from?

• Fibre: Does the bar provide a meaningful amount?

• Fats: What are the amounts and sources of fat and saturated fat?

• Serving size: Does the nutrition panel refer to one whole bar?

• Ingredients: What makes up most of the product?

• Your needs: Are you looking for a post-workout option, an occasional convenient snack or something to help keep you satisfied between meals?

Start with the protein: How much are you actually getting?

If you're buying a protein bar, protein is naturally one of the first things to look at. But don't rely on the product name or front-of-pack claims alone—check the nutrition information panel to see how many grams of protein you're actually getting per bar. 

As a useful benchmark when comparing protein bars, Food Standards Australia New Zealand (FSANZ) specifies that foods making a protein nutrition content claim must contain at least 5g of protein per serve, while a “good source of protein” claim requires at least 10g per serve. 

When comparing protein bars, consider:

• Protein per bar or serving: Check how many grams you'll actually consume rather than looking at the per-100g figure alone. For example, a protein bar may contain 25g of protein per 100g, but if the individual bar weighs only 50g, you're actually getting 12.5g of protein per bar. 

• Serving size: Make sure one serving actually represents the whole bar. Some products may contain more than one serving per package.

• The size of the bar: A larger bar may naturally contain more protein, so comparing similar serving sizes can give you a better idea of the difference between products.

• Your reason for choosing it: The amount you need from a snack will depend on your overall diet, activity level and individual protein requirements.

Where is the protein coming from?

It's also worth looking at the source of protein, as protein bars can be made with very different ingredients. Common sources include:

• Whey protein

• Milk protein

• Collagen peptides

• Soy protein

• Pea or other plant proteins

• Egg protein

• Nuts and seeds

These proteins aren't nutritionally identical. They can differ in their amino acid composition, digestibility and suitability for different dietary preferences or goals. For example, whey is a complete protein containing all nine essential amino acids, while collagen has a different amino acid profile and isn't considered a complete protein.

How much sugar is in your protein bar?

Protein might be the headline ingredient, but sugar is another part of the nutrition panel worth checking. The amount can vary considerably between protein bars, even between products containing similar amounts of protein.

Sugar can enter a protein bar in several ways. Some bars contain sugars added specifically for sweetness, while others use ingredients that naturally contain sugars. Common examples include:

• Sugar, glucose or dextrose

• Glucose syrup, rice syrup or other syrups

• Honey and maple syrup

• Dates and other dried fruits

• Chocolate or chocolate coatings

• Milk ingredients containing naturally occurring lactose

Total sugar vs added sugar

There's also an important distinction between total sugars and added sugars.

Total sugars include sugars naturally present in ingredients as well as sugars that have been added during manufacturing. For example, a bar containing dried fruit or milk ingredients may contain some naturally occurring sugars even if ordinary table sugar hasn't been added.

Added sugars, on the other hand, are sugars and certain sugar-containing ingredients incorporated into a food during manufacturing or preparation.

This means a bar made with ingredients such as dates or honey isn't necessarily "sugar-free" simply because it doesn't contain refined white sugar. These ingredients can still contribute to the bar's overall sugar content.

How much sugar should you look for?

Rather than focusing on one magic number, compare similar products and consider how the bar fits into your overall diet.

When reading the label, ask:

• How many grams of sugar are there per bar or serving?

• How does that compare with other protein bars of a similar size?

• Where does the sugar appear to be coming from?

• Are sugar or syrups among the first few ingredients?

• What else does the bar provide alongside the sugar, such as protein, fibre, nuts or seeds?

In Australia, the nutrition information panel generally lists "sugars" as part of the carbohydrate content, making it relatively easy to compare the amount per serving and per 100g between products.

“Low sugar” doesn't necessarily mean “not sweet” 

Have you ever eaten a protein bar labelled “low sugar” and wondered how it can still taste so sweet? Reducing conventional sugar doesn't necessarily mean manufacturers need to remove sweetness altogether.

Instead, protein bars may use alternative sweetening ingredients to achieve a sweet taste while keeping the amount of sugar in the nutrition panel lower.

Depending on the product, these may include:

• Sugar alcohols (polyols) such as maltitol, erythritol, sorbitol and xylitol

• Steviol glycosides (stevia)

• Monk fruit

• Other permitted sweeteners

These ingredients don't all work in the same way. Some, such as stevia, are high-intensity sweeteners, meaning only relatively small amounts are needed to provide sweetness. Sugar alcohols, on the other hand, can contribute sweetness as well as bulk and texture, making them particularly useful in products such as protein bars.

Why are sugar alcohols used in protein bars?

Sugar alcohols, also known as polyols, are commonly used in protein bars and other reduced-sugar foods as an alternative to conventional sugars. Common examples include maltitol, erythritol, sorbitol and xylitol.

Despite their name, sugar alcohols aren't the same as the alcohol found in alcoholic drinks. They're a type of carbohydrate that can provide sweetness, but they are metabolised differently from regular sugars and generally provide less energy than sugar, although this varies between different polyols.

For protein bar manufacturers, sugar alcohols can be particularly useful because sugar does more than simply make food taste sweet. It can also contribute to the texture, bulk and mouthfeel of a product.

Sugar alcohols may therefore be used to:

• Provide sweetness while reducing the amount of conventional sugar required

• Add bulk and structure to the bar

• Help create a softer or more palatable texture

• Contribute to the mouthfeel of fillings, coatings and other components

• Help manufacturers formulate products that meet certain reduced-sugar or low-sugar claims, where the relevant requirements are satisfied

Are sugar alcohols bad for you?

The presence of sugar alcohols doesn't automatically make a protein bar unhealthy. For many people, foods containing polyols can be consumed without a problem. However, some sugar alcohols are incompletely absorbed in the small intestine, which means they can continue into the large intestine.

For some people—particularly when larger amounts are consumed—this can result in digestive symptoms such as:

• Bloating

• Gas

• Abdominal discomfort or cramping

• Loose stools or diarrhoea

• A laxative effect

How strongly someone reacts can depend on the particular sugar alcohol, the amount consumed and individual tolerance. Someone may be perfectly comfortable after eating one protein bar, for example, but experience symptoms after consuming several polyol-containing products within a short period.

This can also help explain why you might occasionally eat a low-sugar protein bar and feel unusually bloated afterwards. The problem may not necessarily be the protein itself—the bar's sugar alcohols or other ingredients, such as certain added fibres, could be contributing.

In Australia and New Zealand, foods containing certain amounts or types of polyols may also be required to carry an advisory statement about their potential laxative effect, so it's worth checking the label if you know you're sensitive to them.

What are “fillers” in protein bars?

Protein bars need to be more than just a mixture of protein powder pressed into a rectangle. They need to hold together, maintain an appealing texture, retain moisture and remain stable throughout their shelf life. Many of the ingredients sometimes labelled as “fillers” are actually included for one or more of these functional purposes.

Depending on the product, you might find ingredients such as:

• Glycerol (glycerine) – can help retain moisture and keep a bar from becoming excessively dry or hard.

• Gums, such as xanthan gum or guar gum – may be used as thickeners, stabilisers or binding agents.

• Starches – can contribute to structure, thickness and texture.

• Added fibres, such as inulin or chicory root fibre – can increase fibre content while also influencing texture and bulk.

• Emulsifiers, such as lecithin – help ingredients that don't naturally mix well, such as fats and water, remain evenly combined.

• Oils and fats – may be included to improve texture, mouthfeel and consistency.

• Humectants – help retain moisture and prevent the bar from drying out.

So, seeing one of these ingredients on a label doesn't automatically mean it's an unnecessary additive with no purpose. In many cases, it plays a role in making the bar taste, feel and behave the way consumers expect.

Does a longer ingredient list mean a protein bar is less healthy? 

A protein bar with a short ingredient list may appeal to someone looking for a simpler product, but the number of ingredients alone doesn't tell you its nutritional quality. A bar made from only a handful of ingredients could still be high in sugars or saturated fat, while a product with a longer list might provide substantial protein and fibre.

Likewise, an ingredient shouldn't automatically be considered unhealthy simply because its name sounds unfamiliar or is difficult to pronounce. What matters more is what the ingredients are, why they're being used, their quantities where relevant, and the nutritional profile of the product as a whole.

That said, ingredient lists can still be useful when comparing products. In Australia, ingredients are generally listed in descending order by weight, meaning the ingredients present in the greatest amounts appear first. Looking at the first few ingredients can therefore give you a useful indication of what primarily makes up the bar.

Looking for a Better Protein Snack? Shop Chief Nutrition Protein Bars & Healthy Snacks

Chief Protein Bars & Healthy Snacks

Now that you know what to look for on a protein bar label, explore Chief Nutrition’s range of protein bars and better-for-you snacks. Choose from collagen protein bars, Thankful Bars and slow air-dried biltong for convenient, protein-rich snacking at home, at work or on the go.

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