Marketed as a convenient source of nutrition for busy and health-conscious individuals, protein bars have sky-rocketed in popularity on the global market. Although initially intended to boost post-workout recovery for physically active individuals, the abuse of protein bars as low-carbohydrate meal replacements or snacks by all consumers has become prevalent (Jovanov et al. 2021). However, the classification of a protein bar as a “health food” is heavily debated. The usage of artificial additives and the ultra-processing involved in protein bar manufacturing is concerning, especially when regularly ingested (Figure 1).
Figure 1. Nutrition facts label and ingredients list of Pure Protein bar containing 33% of the recommended daily protein intake (“Calories in Protein Bar, Chocolate Deluxe from Pure Protein,” n.d.). The calories are divided into a 44% protein:35% carbohydrates:21% fat macronutrient ratio. Among several artificial additives, some alarming ingredients include: maltodextrin, which has a high glycemic index and can cause blood sugar levels to spike rapidly, or fractionated palm kernel oil, which is high in saturated fat (Hofman, van Buul, and Brouns 2016). Both of these ingredients have been linked to increased obesity and cardiovascular disease (Hofman, van Buul, and Brouns 2016).
An ultra-processed food (UPF) has been engineered beyond resemblance of the raw ingredients from which it was derived (Samuthpongtorn et al. 2023). UPFs have been described to interact with the body in a similar manner to addictive substances like nicotine (Lustig 2020). This is due to how the combination of refined carbohydrates and added fats in UPFs evoke addictive levels of extracellular dopamine in the brain striatum (Samuthpongtorn et al. 2023). A Harvard study conducted from 2003 to 2017 concluded that individuals who consumed nine servings of UPFs instead of four or five experienced a 50% higher risk of developing depression (Samuthpongtorn et al. 2023). Natural protein sources, such as casein and whey in dairy products or legumes and other whole foods, are healthier alternatives.
Protein is a necessary macronutrient, due to its roles in tissue-building, immune protein synthesis, and metabolic regulation. In relation to weight management, protein can have a stimulatory effect on muscle protein anabolism. This helps with lean muscle mass retention while improving metabolic profile (Watford and Wu 2018). A greater reduction in post-prandial ghrelin, an appetite-stimulating hunger hormone that promotes food intake, has been observed after ingesting high-protein foods as well. This results in increased satiety, especially compared to the ingestion of simple carbohydrates or other macronutrients (Missimer et al. 2017). The low-carbohydrate, high-protein, high-fat diet, dubbed the Atkins diet, has been adopted by at least 45 million people worldwide (Astrup, Meinert Larsen, and Harper 2004). Rapid weight loss, enhanced caloric burn, and a diminished appetite are some claims associated with this diet by physicians, dietitians, and other healthcare professionals (Beals et al. 2019). A high protein level is not necessarily beneficial though, and can cause excessive kidney strain (Figure 2).
Figure 2. Glomerulus in the healthy state (A), and glomerulus in an environment of high animal protein intake (B). Increased protein increases the glomerular filtration rate (GFR), resulting in ‘glomerular hyperfiltration’ from a surge in amino acids, dilatation of the ‘afferent’ arteriole (impairing autoregulation), and increased intraglomerular pressure (Kramer 2019). There is currently insufficient data to establish a tolerable upper level for protein consumption. If amino acids are improperly broken down, their toxic by-products can build up in the urine and blood, as seen in various genetic metabolic disorders (Watford and Wu 2018).
Historically, carbohydrates and plant-based fats provided more than 85% of the daily dietary energy intake in the 10-century-old agricultural era, when obesity and type 2 diabetes were uncommon (Konner and Eaton 2010). Protein comprised less than 10-15% of total energy intake until after World War II (Konner and Eaton 2010). This debunks claims attributing the current trend to consume protein as 20-25% or more of one’s daily energy intake to the hunter-gatherer ancestral spirit of humans (Konner and Eaton 2010).
Nonetheless, the global energy bar market was valued at USD 6.02 billion in 2024 and is expected to grow at a compound annual growth rate (CAGR) of 7.6% until 2030 to reach USD 9.92 billion (Grand View Research 2024). Despite their ultra-processed nature, artificial additives, and potential long-term physical and mental health impacts, the market of protein bars is evolving at an economically favourable rate. Ingredient transparency, environmentally sustainable production, and dietary inclusivity are some areas of advancement that could simultaneously increase the economic and health value of protein bars.
Works Cited
Astrup, Arne, Thomas Meinert Larsen, and Angela Harper. 2004. “Atkins and Other Low-Carbohydrate Diets: Hoax or an Effective Tool for Weight Loss?” Lancet (London, England) 364 (9437): 897–99. https://doi.org/10.1016/S0140-6736(04)16986-9.
Beals, Joseph W., Nicholas A. Burd, Daniel R. Moore, and Stephan van Vliet. 2019. “Obesity Alters the Muscle Protein Synthetic Response to Nutrition and Exercise.” Frontiers in Nutrition 6 (June):87. https://doi.org/10.3389/fnut.2019.00087.
“Calories in Protein Bar, Chocolate Deluxe from Pure Protein.” n.d. Nutritionix. Accessed November 25, 2024. https://www.nutritionix.com/i/pure-protein/protein-bar-chocolate-deluxe/51d37963cc9bff5553aa9b0c.
“Energy Bar Market Size To Reach $9.92 Billion By 2030.” Grand View Research, Grand View Research, Sept. 2024, www.grandviewresearch.com/industry-analysis/energy-bar-market-report.
Hofman, Denise L., Vincent J. van Buul, and Fred J. P. H. Brouns. 2016. “Nutrition, Health, and Regulatory Aspects of Digestible Maltodextrins.” Critical Reviews in Food Science and Nutrition 56 (12): 2091–2100. https://doi.org/10.1080/10408398.2014.940415.
Jovanov, Pavle, Marijana Sakač, Mihaela Jurdana, Zala Jenko Pražnikar, Saša Kenig, Miroslav Hadnađev, Tadeja Jakus, Ana Petelin, Dubravka Škrobot, and Aleksandar Marić. 2021. “High-Protein Bar as a Meal Replacement in Elite Sports Nutrition: A Pilot Study.” Foods 10 (11): 2628. https://doi.org/10.3390/foods10112628.
Konner, Melvin, and S. Boyd Eaton. 2010. “Paleolithic Nutrition: Twenty-Five Years Later.” Nutrition in Clinical Practice: Official Publication of the American Society for Parenteral and Enteral Nutrition 25 (6): 594–602. https://doi.org/10.1177/0884533610385702.
Kramer, Holly. 2019. “Diet and Chronic Kidney Disease.” Advances in Nutrition 10 (November):S367–79. https://doi.org/10.1093/advances/nmz011.
Lustig, Robert H. 2020. “Ultraprocessed Food: Addictive, Toxic, and Ready for Regulation.” Nutrients 12 (11): 3401. https://doi.org/10.3390/nu12113401.
Missimer, Amanda, Diana M. DiMarco, Catherine J. Andersen, Ana Gabriela Murillo, Marcela Vergara-Jimenez, and Maria Luz Fernandez. 2017. “Consuming Two Eggs per Day, as Compared to an Oatmeal Breakfast, Decreases Plasma Ghrelin While Maintaining the LDL/HDL Ratio.” Nutrients 9 (2): 89. https://doi.org/10.3390/nu9020089.
Samuthpongtorn, Chatpol, Long H. Nguyen, Olivia I. Okereke, Dong D. Wang, Mingyang Song, Andrew T. Chan, and Raaj S. Mehta. 2023. “Consumption of Ultraprocessed Food and Risk of Depression.” JAMA Network Open 6 (9): e2334770. https://doi.org/10.1001/jamanetworkopen.2023.34770.
Watford, Malcolm, and Guoyao Wu. 2018. “Protein.” Advances in Nutrition 9 (5): 651–53. https://doi.org/10.1093/advances/nmy027.