Protein bars: science and Italian tradition

From NASA to Milan: the Italian roots of 'functional food'

The development of protein bars has its roots in the USA in the 1950s and 1960s, when the first soy protein-based bars were launched (Hi-Proteen Fudge), in 1952, followed by the  Candy Food Bar (1960s) and by the Space Food Sticks for the astronauts of NASA. These products, although rudimentary and not very palatable, inaugurated the concept of concentrated portable nutrition.

In this context,Italy played a pioneering role in Europe thanks to pharmacist Paolo Sorbini, who in 1954 founded Also Laboratori in Milan and in 1973 created the brand Enervit – synthesis of ‘energy’ and ‘vitality’ – dedicated to functional foods for athletes. In 1982 the first ‘Enervit Protein‘ line was launched, previewing integrated nutrition for athletes.

Over time, protein bars have evolved from specialist products for professional athletes to  widely consumed functional foods. The global protein bar market was valued at 14.26 billion dollars in 2024 and is expected to reach 20.05 billion dollars by 2030, with a compound annual growth rate (CAGR) of 5.9% in the 2025-2030 period (Grand View Research, 2025).

Ingredient architecture: beyond biological value

Protein synergies and digestibility indices (PDCAAS/DIAAS)

The nutritional core of protein bars consists of proteins, selected based on biological value, digestibility, and technological functionality. The main sources used include:

• whey proteins, appreciated for their high content of essential amino acids and leucine, with rapid absorption and maximal stimulation of muscle protein synthesis (Tang et al., 2009);

• milk proteins and caseins, characterized by a slower and prolonged amino acid release, thus ideal for maintaining nitrogen balance;

• vegetable proteins (soy, pea, rice, hemp, lupin), increasingly widespread in formulations plant-based o lactose-free, with complementary amino acid profiles (Hertzler et al., 2020);

• hydrolyzed collagen, a highly digestible protein rich in bioactive peptides and amino acids such as glycine, proline, and hydroxyproline. It is valued for its neutral flavor and technological functionality.

Protein quality is evaluated using indicators such as PDCAAS (Protein Digestibility Corrected Amino Acid Score) and DIAAS (Digestible Indispensable Amino Acid Score), which take into account the composition of amino acids and their actual digestibility (Mathai et al., 2025; FAO, 2013).

Functional carbohydrates, prebiotic fibers and sweetening systems

The carbohydrate profile of protein bars shows high variability depending on market positioning. The sources of carbohydrates commonly used include complex carbohydrates (e.g. oat flakes, quinoa, puffed rice), simple sugars (glucose syrups, fructose, honey, dates) and functional dietary fibers (inulin, polydextrose, oligofructose).

The inclusion of  soluble fibers such as inulin (3-5 g per serving) is associated with metabolic benefits, including improved glycemic control and modulation of the gut microbiota. A randomized controlled study showed that high-protein, high-fiber bars reduced postprandial glycemic spikes by 16% compared to conventional bars (Gonzalez et al., 2006).

The reduction of added sugar content has led to the widespread use of  alternative sweeteners. Polyols (maltitol, erythritol, xylitol, sorbitol) have a reduced glycemic index and do not contribute to tooth decay. Other commonly used sweeteners include sucralose, stevia, monk fruit, and natural sweeteners such as date syrups and honey.

Noble lipids: the Omega-3 and Omega-6 balance

Although protein bars are not generally formulated as a primary source of lipids, the quality of the lipid profile assumes nutritional relevance. A balanced ratio of fatty acids Omega-3 and Omega-6 (ideally 1:4 – 1:5) is associated with better modulation of inflammatory responses and long-term metabolic benefits (Simopoulos, 2002).

The inclusion of ingredients such as flax seeds, chia seeds, nuts or dried fruit can help improve this ratio, reducing the excessive prevalence of Omega-6 typical of Western diets.

Technological additives and production process

The formulation of protein bars requires the use of technological additives to ensure stability, texture and palatability: humectants (glycerol, maltitol syrups) to retain moisture, emulsifiers (lecithin) to improve the dispersion of lipid ingredients, gelling agents (carrageenan, xanthan gum) for structure, and possible preservatives for microbiological safety over time.

The production process combines dry ingredients (protein powders, fibers, cereals) and lipid components (cocoa butter, vegetable oils, nut butters) into homogeneous doughs, subsequently shaped by extrusion or molding. The main stages include mixing, forming, possible coating (e.g. chocolate), and modified atmosphere packaging in multilayer plastic films to ensure a shelf-life of 12-18 months.

In advanced industrial contexts, such as those of leading Italian manufacturers, production occurs in plants with dedicated lines for functional bars, equipped with advanced quality control systems. Stabilization is achieved through cold processes or controlled thermal treatments (60-80°C), in order to preserve the nutritional characteristics of proteins and ensure microbiological safety.

Nutritional analysis: energy density and bioavailability

From a nutritional point of view, a standard protein bar provides on average  15–30 g of protein per serving (40-60 g of product), with a variable content of carbohydrates (10-40 g), fibers (3-13 g), and fats (5-15 g) depending on the declared functional goal.

The analysis of over 1,600 commercial protein bars showed that 81% of products meet the EU criteria for the nutritional claim ‘high protein content’ (≥20% of energy from protein), 18% fall into the ‘source of protein’ category (12-20% of energy), while only 1% fails to reach the minimum content (Mathai et al., 2025).

The complex food matrix of bars can moreover influence protein digestibility compared to isolated proteins consumed in liquid or powder form. Simulated digestion in vitro of commercial bars has revealed in some cases lower PDCAAS values compared to pure protein sources, mainly due to the lack of collagen integration with other protein sources, the presence of enzyme digestion inhibitors (phytates, tannins in plant sources), and matrix-nutrient interactions that reduce the bioavailability of essential amino acids, particularly tryptophan (Mathai et al., 2025).

Theglycemic index of protein bars varies considerably (24-70) depending on the carbohydrate composition and fiber and fat content. Optimized formulations with high protein content (>30 g), high soluble fiber content (>8 g), and low glycemic index sweeteners have a GI ≤35, allowing bars to be classified as low glycemic index foods (Basciani et al., 2024).

Innovative formulations based on functional plant ingredients (lupin, wheat germ, nuts) have demonstrated significantly higher contents of phenolic compounds total (up to 57 mg GAE/100 g) and 75% higher antioxidant activity compared to standard formulations, with better oxidative stability during storage (Ahmed et al., 2024).

Scientific validation and health claims

The health properties of protein bars are closely related to their use within the context of a balanced diet. The scientific literature highlights various fields of application, with evidence supported by clinical studies.

Muscle protein synthesis and bone maintenance

The scientific literature shows that an adequate protein intake promotes  muscle protein synthesis, especially when combined with resistance or strength exercise (Phillips & Van Loon, 2011).

The European Food Safety Authority has in turn recognized that proteins contribute to maintenance and to muscle mass growth (EFSA, 2010), and the European Commission has authorized the use of this ‘health claim’ in commercial information related to foods that constitute a ‘source of protein’ (Reg. EU 432/12).

EFSA has also recognized the role of proteins in the formation, development and maintenance of bones (EFSA, 2010). The European Commission has thus authorized a ‘health claim’ on the contribution of proteins to the ‘maintenance of normal bones’, for foods constituting a ‘source of protein’ (EU reg. 432/12).

Post-exercise recovery

A study on elite athletes (professional handball players) showed that consumption of high-protein bars (34 g protein/100 g) containing whey and soy isolates, inulin, creatine and micronutrients results in a significant reduction of exercise-induced muscle damage markers, increased bilirubin levels with antioxidant effect, and improved post-training recovery parameters (Jovanov et al., 2021).

Sense of satiety

Some studies indicate that high-protein snacks may improve the sense of satiety and contribute to the control of daily energy intake. However, EFSA in its 2010 scientific evaluation found insufficient evidence to validate this causal relationship, nor the related ‘health claim’.

A subsequent systematic review found that increasing protein intake from 15% to 25-30% of total energy increases diet-induced thermogenesis, prolongs the sense of satiety through modulation of anorexigenic hormones (GLP-1, PYY), and facilitates maintenance of lean mass during caloric restriction (Leidy et al., 2015).

Nutritional support in sarcopenia

Sarcopenia, defined as the progressive loss of muscle mass and function related to age, affects 6-22% of the elderly and up to 50% of those over eighty (Wu et al., 2025). Scientific literature highlights that older adults require higher protein intakes than younger adults:  1.0-1.2 g/kg/day for healthy subjects,  1.2-1.5 g/kg/day for malnourished subjects or those with acute/chronic conditions (Bauer et al., 2013; Deutz et al., 2014).

The optimal distribution provides 25-30 g of high-quality protein per meal, preferably enriched with leucine (3-4 g), to counteract age-related anabolic resistance (Paddon-Jones & Rasmussen, 2009). Appropriately formulated protein bars can represent a practical vehicle to increase protein intake in elderly subjects with reduced appetite or difficulty in meal preparation, within a complete nutritional plan and associated with physical exercise.

Guidelines for use: from performance to clinical support

Protein bars are primarily used by athletes as nutritional support in different phases of physical activity: pre-workout with balanced formulations, during prolonged activities with a carbohydrate:protein ratio of 3:1 or 4:1, post-workout with 20-30 g of high biological value protein to maximize muscle protein synthesis, and as between-meal snacks to maintain a positive nitrogen balance. The convenience of single-dose format and ease of dosing make bars particularly advantageous in competitive or intensive training contexts.

Their use has progressively extended to other contexts:

• balanced breakfast, especially for those who need immediate protein intake and do not have time for elaborate preparations;

• partial meal replacements in controlled calorie restriction programs, or functional snacks between main meals, also in vegetarian and vegan versions;

• nutritional support for the elderly. To increase daily protein intake in a practical and palatable way, especially in subjects with reduced appetite;

It is important to consider this type of product as a  component of the diet and not as a systematic substitute for fresh and minimally processed foods. Potential critical issues include gastrointestinal disorders from excessive consumption of polyols (>20-30 g/day), excessive protein intake that may overload kidney function in predisposed individuals, high content of saturated fats and added sugars in some products.

Conclusions

Italian protein bars are positioned at the intersection of food innovation, sports nutrition, and everyday convenience. Their nutritional effectiveness depends on the quality of protein sources, the lipid profile, the sweetening system used, and the overall balance of macronutrients. Scientific research supports their targeted use, particularly in sports, weight management, nutritional support for the elderly, and sarcopenia prevention, within a modelof balanced and conscious eating. Critical evaluation of the nutrition label and ingredient list remains essential to guide informed consumption choices.

Dario Dongo

Credit cover: Enervit SpA 

References

• Ahmed, I. A. M., Uslu, N., Özcan, M. M., Al Juhaimi, F., Babiker, E. E., Ghafoor, K., & Banerjee, P. (2024). Development and characterization of high-energy protein bars with enhanced antioxidant, chemical, nutritional, physical, and sensory properties.  Foods, 13(2), 259. https://doi.org/10.3390/foods13020259

• Basciani, S., Camajani, E., Contini, S., Persichetti, A., Risi, R., Bertoldi, L., Strigari, L., Prossomariti, G., Watanabe, M., Mariani, S., Lubrano, C., Spera, G., Lenzi, A., Gnessi, L., & Donini, L. M. (2024). A comprehensive study on the nutritional profile and shelf life of a custom-formulated protein bar versus a market-standard product. Nutrients, 16(12), 1851. https://doi.org/10.3390/foods14122141

• Bauer, J., Biolo, G., Cederholm, T., Cesari, M., Cruz-Jentoft, A. J., Morley, J. E., Phillips, S., Sieber, C., Stehle, P., Teta, D., Visvanathan, R., Volpi, E., & Boirie, Y. (2013). Evidence-based recommendations for optimal dietary protein intake in older people: A position paper from the PROT-AGE Study Group.  Journal of the American Medical Directors Association, 14(8), 542–559. https://doi.org/10.1016/j.jamda.2013.05.021

• Commission Regulation (EU) No 432/2012 of 16 May 2012 establishing a list of permitted health claims made on foods, other than those referring to the reduction of disease risk and to children’s development and health. Consolidated text: 20/08/2025 http://data.europa.eu/eli/reg/2012/432/2025-08-20

• Deutz, N. E., Bauer, J. M., Barazzoni, R., Biolo, G., Boirie, Y., Bosy-Westphal, A., Cederholm, T., Cruz-Jentoft, A., Krznariç, Z., Nair, K. S., Singer, P., Teta, D., Tipton, K., & Calder, P. C. (2014). Protein intake and exercise for optimal muscle function with aging: Recommendations from the ESPEN Expert Group.  Clinical Nutrition, 33(6), 929–936. https://doi.org/10.1016/j.clnu.2014.04.007

• European Food Safety Authority, EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA). (2010). Scientific Opinion on the substantiation of health claims related to protein and increase in satiety leading to a reduction in energy intake, contribution to the maintenance or achievement of normal body weight, maintenance of normal bone, and growth or maintenance of muscle mass pursuant to Article 13(1) of Regulation (EC) No 1924/2006 (EFSA Journal 2010;8(10):1811). https://doi.org/10.2903/j.efsa.2010.1811

• Enervit S.p.A. (2023).  Company profile and history. Enervit Group.

• FAO. (2013).  Dietary protein quality evaluation in human nutrition (FAO Food and Nutrition Paper No. 92). https://www.fao.org/4/i3124e/i3124e.pdf

• Giacosa, A., Barrile, G. C., Mansueto, F., & Rondanelli, M. (2024). The nutritional support to prevent sarcopenia in the elderly.  Frontiers in Nutrition, 11, 1379814. https://doi.org/10.3389/fnut.2024.1379814

• Grand View Research. (2025).  Protein bar market size, share, growth, trends report, 2030. https://www.grandviewresearch.com/industry-analysis/protein-bar-market-report

• Hertzler, S. R., Lieblein-Boff, J. C., Weiler, M., & Allgeier, C. (2020). Plant proteins: Assessing their nutritional quality and effects on health and physical function.  Nutrients, 12(12), 3704. https://doi.org/10.3390/nu12123704

• Leidy, H. J., Clifton, P. M., Astrup, A., Wycherley, T. P., Westerterp-Plantenga, M. S., Luscombe-Marsh, N. D., Woods, S. C., & Mattes, R. D. (2015). The role of protein in weight loss and maintenance.  The American Journal of Clinical Nutrition, 101(6), 1320S–1329S. https://doi.org/10.3945/ajcn.114.084038

• Mathai, J. K., Liu, Y., & Stein, H. H. (2025). Evaluation of protein quantity and protein nutritional quality of protein bars with different protein sources.  Scientific Reports, 15, 94072. https://doi.org/10.1038/s41598-025-94072-4

• Paddon-Jones, D., & Rasmussen, B. B. (2009). Dietary protein recommendations and the prevention of sarcopenia.  Current Opinion in Clinical Nutrition & Metabolic Care, 12(1), 86–90. https://doi.org/10.1097/MCO.0b013e32831cef8b

• Phillips, S. M., & Van Loon, L. J. C. (2011). Dietary protein for athletes: From requirements to optimum adaptation.  Journal of Sports Sciences, 29(S1), S29–S38. https://doi.org/10.1080/02640414.2011.619204

• Simopoulos, A. P. (2002). The importance of the ratio of omega-6/omega-3 essential fatty acids.  Biomedicine & Pharmacotherapy, 56(8), 365–379. https://doi.org/10.1016/S0753-3322(02)00253-6

• Jovanov, P., Sakač, M., Jurdana, M., Pražnikar, Z. J., Kenig, S., Hadnađev, M., Jakus, T., Petelin, A., Škrobot, D., & Marić, A. (2021). High-Protein Bar as a Meal Replacement in Elite Sports Nutrition: A Pilot Study.  Foods (Basel, Switzerland), 10(11), 2628. https://doi.org/10.3390/foods10112628

• Tang, J. E., Moore, D. R., Kujbida, G. W., Tarnopolsky, M. A., & Phillips, S. M. (2009). Ingestion of whey hydrolysate, casein, or soy protein isolate: Effects on mixed muscle protein synthesis at rest and following resistance exercise in young men.  Journal of Applied Physiology, 107(3), 987–992. https://doi.org/10.1152/japplphysiol.00076.2009

• Wu, W., Chen, F., Ma, H., Lu, J., Zhang, Y., Zhou, H., Yang, Y., Nie, S., Wang, R., Yue, W., Li, M., & Yang, X. (2025). Dietary protein requirements of older adults with sarcopenia determined by the indicator amino acid oxidation technology.  Frontiers in Nutrition, 12, 1486482. https://doi.org/10.3389/fnut.2025.1486482