Protein bars: are they really healthy?

Author: Derry Procaccini

A protein bar can be convenient and have a place in your diet, but the word “protein” is not enough to make it healthy. What matters is the quality of the protein, the overall composition, the portion size and why we are eating it. Developing a bar that balances these factors with taste, texture and storage stability is a real challenge. Recent studies help explain why, without justifying a negative judgement of the entire category.

For Swiss Natural Med, this challenge remains unresolved: none of our attempts so far has met all our quality standards. We continue to work on it, but for now we do not offer bars in our range. Here we explain which aspects deserve attention and how to assess a product beyond the promises on its packaging.

Sports bars, protein bars and energy bars: what is the difference?

“Sports bars” is a broad term. Two products that look similar can have very different compositions and purposes: one may prioritise protein, another the carbohydrates needed to fuel prolonged exercise. They should not be judged by the same criteria.

The commercial category is no substitute for reading the label. An energy bar is not necessarily a good source of protein; a protein bar is not automatically the most suitable fuel during a race.

Before, during or after exercise: which bar do you actually need?

The ideal bar depends on your goal and when you will use it. Fuelling a race and supporting muscle recovery call for different priorities: the highest possible protein content is not always the most useful feature. Duration, intensity, previous meals and digestive tolerance complete the assessment. ^{14, 15}

The nutritional priorities come from sports nutrition guidance; packaging and chewability are practical design criteria. No table can replace checking your own tolerance. ^{4, 14, 15}

Before: available energy without feeling weighed down

The closer you are to the start, the more portion size and ease of digestion matter. A bar very high in protein, fat or fibre may be unsuitable at this point, especially for people who experience gastrointestinal problems. This does not mean these nutrients are undesirable in an everyday diet. ¹⁴

A bar can complement a planned snack, but it should not automatically be added to a meal that is already sufficient. The useful amount depends on what you have eaten and the effort ahead. Try a new formulation in training rather than tasting it for the first time on race day. ^{4, 14}

During: endurance is mainly about fuel

During a short, easy session, you may not need a bar at all. During prolonged exercise, however, a carbohydrate-rich energy bar can help provide fuel: a low-carbohydrate protein bar does not do the same job. ^{14, 16}

As a guide, endurance activities lasting around 1–2.5 hours often involve 30–60 g of carbohydrates per hour; beyond approximately 2.5–3 hours, intake can reach 90 g per hour, using carbohydrate blends and with trained digestive tolerance. These are total amounts from foods, gels and drinks, not targets that must be met with bars alone. They are not a universal goal for every workout. ^{14, 16}

An example of reading the label: a hypothetical bar containing 20 g of protein and 5 g of carbohydrates contributes only 5 g towards carbohydrate fuelling, not 25. The word “protein” does not make it an equivalent substitute for an energy bar.

When you are moving, being able to take small bites and the texture at the expected temperatures also matter. If chewing is awkward or solid food is poorly tolerated, the plan can include other formats. A bar does not replace a hydration plan. ^{4, 16}

After: essential amino acids and energy recovery

Here, a protein bar can play a practical role if it provides quality protein and fits your daily needs. ISSN guidance commonly refers to 20–40 g of high-quality protein per intake, adjusted to the individual: this is not a mandatory amount for every bar, nor does declaring it on the label establish protein quality. ¹⁵

After a long race, or when another session is coming up soon, carbohydrates also need consideration. A bar with almost no carbohydrates may contribute to protein intake, but cannot replenish energy stores on its own. Overall diet also matters: there is no obligation to eat a bar within a few minutes, especially if an appropriate meal is already planned. ¹⁵

Why one recipe is not optimal for every occasion

A bar designed for recovery may prioritise protein; one intended to provide fuel during a race should primarily make carbohydrate intake convenient. Seeking maximum protein, very little sugar and rapid energy replenishment all at once means assigning different objectives to the same recipe.

This also clarifies SNM’s project: a high intake of essential amino acids is a goal for our future protein bar, not a universal criterion for every sports bar. The intended use must be defined before judging the formulation.

Plenty of protein, but potentially very low nutritional quality

A bar can contain plenty of protein yet have very low protein quality. This was the key concern identified in a 2025 study: after examining nutritional data for 1,641 bars, researchers subjected four selected products to simulated digestion. All showed low protein quality scores; the highest in vitro estimated DIAAS was 61, while the bar containing milk protein, collagen and soy scored below 10. These are not percentages of protein absorbed in humans. ¹

The issue is essential amino acids, which we must obtain from food: what matters is not just how many grams of protein a product contains, but which amino acids it provides and how available they are after digestion. Collagen can increase total protein without providing an equivalent amount of essential amino acids. Its combination with other ingredients can also influence their availability. ¹

The concern is real, but the study does not show that most bars use very poor-quality protein: the experimental assessment covered four products, and the result also depends on the final formulation, not just the raw ingredient. ¹

For more detail, read about the difference between amino acids and proteins.

Why developing a good bar is complicated

A bar needs to remain pleasant to eat, be portable and retain suitable characteristics during storage. Increasing one ingredient or reducing another can simultaneously change taste, structure and behaviour over time.

Protein, softness and storage stability must work together

In a 2025 study, experimental bars made with pea, whey or rice protein became harder during six weeks of storage. The researchers also examined protein and fat oxidation, highlighting how much stability depends on the formulation. ²

The practical implication concerns product development: achieving a pleasant texture on the day of manufacture is not enough. Its evolution needs to be assessed. Hardening or an oxidation marker measured in a laboratory does not, on its own, demonstrate harm to the health of someone eating a bar. The study was not a clinical trial investigating that question. ²

Reducing sugar does not solve every problem

A review published in 2026 describes strategies to modify the glycaemic response to energy bars by changing carbohydrate sources and using fibre and sugar substitutes, among other ingredients. It shows that some formulation parameters can be improved. ³

However, a lower glycaemic index does not automatically mean fewer calories, nor does it establish that the product improves long-term health. The review mainly addresses formulation characteristics and glycaemic response, rather than providing definitive evidence of clinical benefit. ³

The right question therefore becomes: what goal should this bar meet? An everyday snack and a food used during prolonged sporting activity serve different needs.

Digestive tolerance matters too

During exercise, the digestive system can respond differently than at rest. A 2025 sports nutrition consensus statement highlights individual variation in gastrointestinal symptoms and the importance of adapting food choices and intake strategies to the person and the activity. ⁴

A bar’s tolerance should therefore be tested under the conditions in which it will be used, preferably during training before a race. “I like it” and “I digest it well while running” are not the same assessment. Fibre and sweetening ingredients should be considered in the context of the formulation and individual response, without treating any single ingredient as universally to blame.

From the laboratory to your backpack: heat, cold and months without refrigeration

Imagine the same bar freshly made, after weeks in a warehouse and during a hike. Consumers want it to taste good, be easy to chew and be convenient to carry every time. Manufacturers must translate those expectations into storage conditions and measurable tests. There is no generic resistance to “everything”.

Heat tests more than just shape

In an experiment published in 2020, 15 formulations containing different proteins and sweeteners were stored at 35 °C and 55% humidity for 35 days. Researchers tracked taste and texture over time: changing the protein source or sweetener altered the product’s behaviour. An accelerated test of this kind is used to study stability; it does not automatically justify promising a particular number of months of shelf life in any environment. ⁶

For a chocolate-coated bar, the behaviour of the coating adds another factor. Heat and subsequent cooling can alter the arrangement of fats and promote the whitish coating known as fat bloom, affecting appearance and perceived quality. A 2025 paper explains why composition alone is not enough: crystallisation during processing also determines stability. This evidence concerns chocolate and is relevant to coatings; it is not a test of all protein bars. ⁷

Cold also needs to be tested

A bar intended to be eaten outdoors should also be assessed at the actual temperature of consumption: can you bite and chew it? Does the coating retain the desired characteristics? How does it respond to moving from a cold environment to a warm one?

These are product development questions, not findings already established for every formulation. Research on chocolate crystallisation shows how much cooling and thermal history matter. It does not, however, provide a universal minimum temperature for every bar. ⁷

“Can be stored without refrigeration” means that the product was designed for specific conditions, not that it can equally be left in a car in the sun, in a winter backpack or on a damp shelf. Storage instructions are part of the conditions under which shelf life must be assessed.

Without a cold chain: the delicate balance of water

To understand storage stability, we need to distinguish how much water a food contains from how much is available to microorganisms and reactions. This second property is called water activity. It cannot simply be inferred by touching a bar or judging it to be soft.

Ingredients such as glycerol can help manage available water and texture. A 2009 study of whey protein-based model systems compared different polyols: glycerol was particularly effective at reducing water activity and maintaining a soft structure. This is a technological example, not a reason to consider that ingredient essential or all formulations identical. ⁸

Reducing available water, however, is not the same as sterilising. The literature on low-moisture food safety reminds us that some pathogens can persist: raw material quality, hygiene and process control remain essential. The cited 2024 review concerns this general category of foods; it does not demonstrate that commercially available bars are contaminated. ⁹

The task is therefore twofold: achieve verified stability without making the product unpleasant to eat. Simply adding water to soften it, or removing water to preserve it, does not solve the whole problem on its own.

Shelf life: packaging also determines how long a bar lasts

Shelf life is the period during which a food maintains defined safety and quality requirements under the intended conditions. It is not only about the appearance of mould: taste, smell, texture and packaging integrity are all part of the assessment.

A study of protein-rich composite bars, published in 2012, compared different packaging materials, including vacuum packaging, at ambient temperatures ranging from 15 to 34 °C and at 37 °C. Hardening was a limiting factor for shelf life, despite chemical and microbiological stability under the conditions studied. ¹⁰

The point is practical: a bar can become unpleasant to eat before showing a microbiological problem. Packaging is more than a surface for branding: its ability to limit exchanges with the outside environment contributes to preservation. Another experiment, from 2005, found significant effects of different packaging barriers on bar stability during six months of storage. ¹¹

These studies are older, but address the issue directly. They are included alongside newer studies, without being presented as research from 2025 or 2026.

Why does the industry use sweeteners, flavourings, emulsifiers and preservatives?

These ingredients address different problems. They are not all present in every bar, and they are not interchangeable. The table distinguishes their general functions; it does not describe any particular brand’s recipe. ^{6, 8, 12, 13}

Taste provides an interesting example: in the 2020 study, some formulations with stevia or monk fruit had bitter or metallic notes. The sweetener’s plant origin did not guarantee a perfect sensory solution. The finding concerned those recipes, not every product containing these ingredients. ⁶

It is more precise to discuss flavourings and their functions than to treat “chemical flavourings” as a risk category. Similarly, knowing an additive’s family is not enough to determine its health effects: information on the substance, amounts and exposure is needed. Reviews of additives and plant-based alternatives describe different functions and limitations, rather than a simple divide between “natural is good” and “synthetic is bad”. ¹²

The hardest compromise: meeting every requirement at once

Consumers may want plenty of protein, little sugar, few ingredients, good taste, softness, digestive tolerance and a long shelf life. Manufacturers must also achieve repeatable results during processing and distribution. The difficulty arises when the same recipe is expected to meet all these requirements simultaneously.

Reducing an ingredient may require restoring a function elsewhere: sweetness, structure or water management. Choosing a different protein can change texture and taste. A coating adds another component that needs stabilising. This does not mean every change necessarily requires a new additive, but that the recipe must be reassessed as a whole. ^{6, 7, 8}

Convincing evidence must therefore concern the finished product: when freshly made, throughout its intended storage period and under the stated conditions of use. Technological tests verify stability and quality; on their own, they do not demonstrate long-term clinical benefits.

Is a short ingredient list enough?

No. It can make a product easier to understand, but counting ingredients is no substitute for a nutritional assessment.

A 2026 study analysed 1,930 products across five food categories in Québec, including 369 cereal bars. Associations between ingredient count and nutritional quality varied across categories and scoring systems. The authors concluded that ingredient count alone is not a reliable indicator. ⁵

The study was not exclusively about protein bars and did not measure consumers’ health outcomes. It does, however, help avoid a common shortcut: “few ingredients” does not automatically mean “a balanced product”. Likewise, a longer list does not, on its own, show that a food is harmful. ⁵

Why Swiss Natural Med does not sell bars, for now

At Swiss Natural Med, we have set ourselves very high quality standards. So far, none of our attempts to develop a bar that meets all of them at once has achieved that goal. That is why we do not offer one in our range.

We want to create a bar with a high amount and balanced profile of essential amino acids, without artificial sweeteners, without artificial flavourings and without additives whose safety remains uncertain under our assessment criteria. The last point is an internal precautionary criterion, not a blanket judgement on all additives or other manufacturers’ bars.

These requirements must be accompanied by good taste, good digestive tolerance, a satisfying texture and stability without a cold chain, for the intended shelf life and under the expected storage and use conditions. A recipe working when freshly prepared is not enough: the finished product must retain its expected characteristics throughout its commercial life.

So far, we have not been able to meet all these requirements according to our standards. We will continue working on it. We would rather wait for a solution we consider suitable before bringing a bar to market.

This reflects our development experience and our business decision. It does not mean that scientific research shows it is absolutely impossible to produce a good bar.

My view: are we looking for sports nutrition or a sweet treat?

A reflection by Derry Procaccini, the author of this article

If, to make a bar appealing and easy to sell, protein quality is sacrificed and its taste is built around artificial sweeteners, flavourings and colours, alongside additives for which I believe stronger safety assurances are needed, I wonder what the “sports” promise actually means. The risk is that buyers, attracted by taste and packaging, pay little attention to what the formulation really provides.

My provocative point is this: if what I mainly want is a sweet treat, I might as well consciously choose a classic confectionery bar, such as Mars or Snickers, without attributing sports benefits to it that I have not checked. The comparison is about informed purchasing: I am not claiming that these products are nutritionally equivalent to or better than a protein bar.

If, instead, I am looking for food to support sport, I want to know which proteins it contains, how much it provides in essential amino acids and whether its composition suits the time when I will use it. I also want to understand the role of the other ingredients. I do not regard artificial origin alone as evidence of danger: my criterion is to assess the formulation rigorously, without allowing taste and marketing to replace nutritional quality.

Anyone looking for a sports bar should learn about its composition, rather than stopping at the words “high protein”. That is the awareness I would like to encourage.

Derry Procaccini

How to assess a bar before buying it

You can use five practical questions:

1. What do I need it for? A snack, protein intake and fuelling during exercise are different goals.
2. What does the whole serving provide? Compare energy, protein, sugars, saturated fat, fibre and salt. Values per 100 grams help with comparisons; values per serving describe what you will eat.
3. What are the protein sources? Read the ingredients: the total number of grams does not, on its own, describe protein quality.
4. How well do I tolerate it? Consider the amount, timing and your own digestive response, especially if you use it during physical activity.
5. What does it replace or add to my diet? The assessment changes depending on whether it meets an occasional practical need or becomes an automatic choice disconnected from meals and your requirements.

You do not need to find one number that declares a bar “good” or “bad”. You need to understand whether that product, in that amount and in that context, is suitable for you.

Frequently asked questions about protein bars

Are protein bars good or bad for you?

There is no single answer for the entire category. A high protein content does not certify overall quality, but being in bar form does not automatically make a food harmful either. Composition, portion size, frequency and overall diet all need consideration.

When should you eat a protein bar?

Timing depends on the goal: before exercise, available energy and digestion matter; during prolonged exercise, carbohydrates take priority; afterwards, a protein bar can contribute to recovery if it provides quality protein. None of these occasions makes eating a bar mandatory. ^{14, 15, 16}

How many protein bars per day?

There is no number that applies to everyone. The amount depends on the product and what you consume in the rest of your diet. The starting point is your overall requirements, not a daily quota of bars to reach.

Is a homemade bar necessarily healthier?

Making it yourself allows you to choose the ingredients and portions, but does not automatically guarantee a better nutritional profile. A homemade recipe also needs to be assessed for composition, quantity and suitability for its intended use.

Scientific references

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3. Sasikumar R et al. Review of low-glycaemic-index carbohydrates in energy bars. Journal of the Science of Food and Agriculture, 2026. PubMed, PMID 42252591. DOI: 10.1002/jsfa.70775.
4. Costa RJS et al. Consensus statement on preventing and managing exercise-associated gastrointestinal symptoms. Sports Medicine, 2025;55:1097–1134. PubMed, PMID 40195264. DOI: 10.1007/s40279-025-02186-6.
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7. Chocolate Tempering: A Perspective. Crystal Growth & Design, 2025;25:2764–2783. PubMed, PMID 40352747. DOI: 10.1021/acs.cgd.5c00269.
8. Liu X et al. Polyols and whey protein stability in intermediate-moisture model food systems. Journal of Agricultural and Food Chemistry, 2009;57:2339–2345. PubMed, PMID 19231894. DOI: 10.1021/jf802789y.
9. Karuppuchamy V, Heldman DR, Snyder AB. Low-moisture food safety and dry-cleaning methods: a review. Journal of Food Science, 2024;89:793–810. PubMed, PMID 38221802. DOI: 10.1111/1750-3841.16920.
10. Padmashree A et al. Development of a shelf-stable protein-rich composite bar. Journal of Food Science and Technology, 2012;49:335–341. PubMed, PMID 23729853. DOI: 10.1007/s13197-011-0283-6.
11. Cereal bars with soy protein and wheat germ: physicochemical characteristics and texture during storage. 2005. PubMed, PMID 16454057.
12. Review of synthetic additives and opportunities to replace them with plant-based ingredients. Food Research International, 2024. PubMed, PMID 39593388. DOI: 10.1016/j.foodres.2024.115177.
13. Review of technologies for emulsifying and stabilising lipophilic ingredients in food. 2024. PubMed, PMID 38873677.
14. Thomas DT, Erdman KA, Burke LM. Position statement on nutrition and athletic performance. Journal of the Academy of Nutrition and Dietetics, 2016;116:501–528. PubMed, PMID 26920240. DOI: 10.1016/j.jand.2015.12.006.
15. Kerksick CM et al. ISSN position stand on nutrient timing. Journal of the International Society of Sports Nutrition, 2017;14:33. PubMed, PMID 28919842. DOI: 10.1186/s12970-017-0189-4.
16. Review of carbohydrate intake strategies in prolonged endurance exercise. Nutrients, 2025;17:918. PubMed, PMID 40077786. DOI: 10.3390/nu17050918.