Protein is a fundamental component of human nutrition from birth in order to guarantee tissue building and repairing [11]. Worldwide population growth, increase in income and urbanization determined an increase in animal protein demand [12].

Recent literature has underscored that insect-derived protein can provide a sustainable and ecological substitute for animal protein [13, 14]. Approximately 1900 species of insects have been documented as edible [15]. Many of those species can be directly collected form nature employing very little expenses and thus, their harvesting is suitable also for low-income countries [15]. Another potential benefits derive from the cultivation process of these products, which has been shown to generally use less land and water [16] and result in lower greenhouse gas emissions [16, 17] compared to livestock farming. In addition, with a planet home to 648 million people, 8.4% of the world's population lives in extreme poverty (< $2.15/day) according to the World Bank, the insect market could represent an interesting new market development for farmers in rural communities in developing countries [18, 19] or a new form of business and income for Western countries [20, 21]. For all the above reasons insect food consumption could impact positively the environment.

It is important to highlight that despite current media tendence to use the EFSA term “novel foods” with the meaning of new foods, insect-based foods were used from the ancient Greek [22]. Moreover, insect has always been part of human diet for more than 2 billion inhabitants of Asia, Africa, South America and Oceania [15].

Although there is a wide variety of edible insects worldwide, most of them have in common that they consist mainly of high amounts of protein, monounsaturated and polyunsaturated fats and dietary fiber [17]. Analyzing in particular the products that have been approved on the EU market, we have a protein percentage that varies from the lowest 14% for frozen form of migratory locusts or house rickets to the higher level of around 75% for house crickets partially defeated powder. All nutrient contents of the approved products are given in Fig. 1.

Composition of the novel insect-based foods marketed to date based on EFSA assessments. LM: Locusta Migratoria, TM: Tenebrio Molitor, AD: Acheta Domesticus

Another possible benefit of insect-based food would be supplementation of mineral deficiency like iron deficiency anemia because they are believed to be very rich in iron. If we carefully analyze iron content in the insect feeds approved it varies from 4 to 8 g/100g [6,7,8, 10]. Furthermore, two recent RCT conducted in young females (18–45 years) reported conflicting results. While mealworm fortification [23] seems to provide a high non heme iron absorption, house rickets [24] showed a low iron absorption rate. No study to date has evaluated this specific topic in children.

Edible insects have always played a major role in oriental medicine because of their potential therapeutic role [25]. A recent publication has further explored the role of bioactive compounds such as polyphenols and flavonoids found in edible insects as antioxidants, anti-inflammatory, antibacterial and insulin regulators [26,27,28]. The content of polyphenols in insect-based food was recently summarized in a review and varied from 0.3 to 5 g of Gallic Acid Equivalent in 100 g [17]. Up-to date we do not dispose of any publication on the potential anti-inflammatory role of insect-based food in children.

From the analysis of the insect-based food composition, EFSA was able to underline that the main constituent of the fibers of these products is chitin (Fig. 2).

percentage of chitin on total fibers in insect-based NFs based on EFSA assessments. LM: Locusta Migratoria, TM: Tenebrio Molitor, AD: Acheta Domesticus. * data not available

It is a linear polysaccharide composed of b-(1,4)-linked 2-amino-2-deoxy-b-D-glucopyranose and 2-acetamido-2-deoxy-b-D-glucopyranose residues [29]. Chitin poses a problem in estimating the true protein content of NFs. As recently reported by Janssen et al. [30], using the usual nitrogen-to-protein conversion factor of 6.25 overestimates the protein content due to the high non-protein nitrogen, which originates from chitin. A factor in the range of 4.7 to 5.6 depending on the different content in different NFs would be more appropriate with an overestimation of the protein content in the range of 24% and 11% [6,7,8,9,10].

A recent literature review on the subject attempted to summarize the potential effect of edible insects in infant nutritional supplements [31]. A careful selection provided 12 articles originating from Africa (10) and Asia (2), none from western countries. Five of the 12 studies examined the supplemental use of crickets, but only three were published [32,33,34] and one on migratory locusts [35]; the rest were from non-commercialized insect NF, none from yellow mealworm. The insect-based formulations exceed the recommended daily amount of energy, protein and fat for complementary foods for children aged 6 to 23 months. However, only one [32] of the five studies on rickets analyzed post-intervention nutritional status and found an increase in the prevalence of stunting in the cricket group from 20.7% at baseline to 43.2% after six months of intervention. In addition, Hb and ferritin levels increased between baseline and endline in all groups, including the control group.

Cases of allergic reactions and possible anaphylaxis have been reported as early as 1999 from the use of locusts in China [36] and crickets in Thailand [37]. Recently, the same possible allergic reaction was reported for yellow mealworms [38, 39]. In addition to the direct allergic response described, some studies have highlighted that edible insects may share some of the same allergenic epitopes with other insects such as arthropods, mollusks or nematodes [40, 41]. For all these reasons, EFSA emphasized that ingestion of insect-based NFs authorized on the EU market may trigger a primary allergic reaction or cause cross-reactivity in patients allergic to crustaceans and dusts. In addition, a more thorough analysis of these products by EFSA suggests that possible allergens (particularly gluten) could be part of insect-based feed and thus represent another source of allergens [6,7,8,9,10]. However, it is important to highlight that none of the aforementioned report included pediatric patients, thus, there are no evidence to prohibit those food to atopic/allergic children.