Edible Insects & Nutritional Content

Forgetting for a moment, the huge potential ecological impact that incorporating bugs into our diets can have on our global resources, what kind of nutritional value do edible insects actually have? Well, as I’m sure you can imagine, this varies incredibly with the species we’re talking about, but most are high in protein and for some, this even exceeds that of your leanest cuts of beef.

Grab Some Grub Infographic
Grab Some Grub | © South China Morning Post

Based on the 2013 report by the Food and Agriculture Organization of the United Nations, the South China Morning Post put together an interesting infographic on entomophagy, showing the protein and fat contents of the most popular edible insects throughout the world. The validity of some of their examples will again be dependent on the species, and the comparisons between these and more conventional sources of protein will have a different outcome depending on whether you’re talking about fresh or dried weight, but it’s a really informative infographic nonetheless.

Unfortunately, however, this compares protein contents between bugs and more readily accepted protein sources at different weights, which kind of defeats the point if you ask me. It shows the protein content in 100 grams of each of the edible insects, yet only gives you the protein content of 85 grams of beef, one cup of milk, or one egg.

It also fails to take into account the variation found within each species. For example, it shows that crickets have only 9.6 grams of protein per 100 grams of fresh weight, but studies in the UN report give this figure as a range from 8-25 grams per hundred.

So in order to give you a more representative comparison between edible insects and some other protein sources, I summarised the data from the UN report on fresh weight protein content in the graph below (FAO, 2012).

Protein Content of Edible Insects

You will notice from the graph that most of the edible insects studied have protein levels very comparable to beef. The exception seems to be the silkworm, a favourite street food item in South Korea (but one that I have sadly never been able to acquire a taste for)! You can see that the one that stands out way above the rest is the “Chapuline” which is actually a type of grasshopper (genus: Sphenarium) eaten in a variety of ways in Mexico.

Edible Insects & Protein Content
Protein content per 100 grams fresh weight of edible insects, beef, mackerel and shrimp (data from FAO, 2012)

If we now take mealworms as an example (since they are our farm bug of choice), the protein content of fresh weight ranges from 14 to 25 grams per hundred. Now if you were to dry-roast your mealworms, the protein content jumps to a whopping 55% and you still retain a good chunk of those vitamins, minerals and polyunsaturated fats (including Omega-3 and 6). You can see what I’m getting at here… bugs are incredibly nutritious! But let’s take this a little further and look at the essential amino acid content. Amino acids are the protein building blocks of our bodies and around 500 are known to science, but as far as human nutrition is concerned, these are classified into 22 functional groups. All but nine of these can be synthesised by our bodies out of other molecules, and these nine therefore have to be taken up through our food. They are called the “essential” amino acids and are what we’ll focus on.

Edible Insects and Essential Amino Acids
Comparison of essential amino acid content between mealworms and three other protein sources (mealworm data from Ghaly & Alkoaik, 2009)

When you’re talking protein content, the most rigorous comparisons you can make are with leading protein powder products designed for athletes and body builders. I won’t go into which brands we are using for comparison here, but they represent the elite in the UK for each protein source. Even if you compare 50 grams of pure, dried, untreated mealworms (Ghaly & Alkoaik, 2009) with the same mass of premium quality (and crucially, fortified) protein powder, mealworms hold their own pretty well, as can be seen in this graph. The numbers here represent the percentage of your Daily Requirements (WHO/FAO/UNU, 2007) for all nine essential amino acid categories that you will get from 50 grams of each protein source.

Fatty Acid Content

As evidenced from data collated in the UN report, beef contains more non-essential fatty acids such as palmitoleic, palmitic and stearic acid than mealworms, and the two are rather similar in their essential Omega-3 content. However, far higher values in essential Omega-6 were found in mealworms (Finke, 2002).

Beef

Omega-3 Polyunsaturated 3.9 g/kg
Omega-6 Polyunsaturated 10.8 g/kg

Mealworms

Omega-3 Polyunsaturated 3.7 g/kg
Omega-6 Polyunsaturated 91.3 g/kg

Vitamin & Mineral Content

Much like protein and fat content, the amounts of vitamins and minerals found in edible insects varies considerably between species. Most contain high levels of the B vitamins essential for metabolic processing and when compared with beef, for example, mealworms have higher levels for all except Vitamin B12. By dry weight, 100 grams of both mealworms and crickets provide well over our daily requirements of Vitamins B2, B5, B7 and B9, with relatively high levels of Vitamins B1 and B3 (Finke, 2002). Although poorly represented in most edible insects, mealworms and crickets are among the best Vitamin B12 sources identified so far.

As far as minerals are concerned, edible insects are considered to be particularly rich in iron and zinc, comparable to and in some cases much more so than beef. The World Health Organization (WHO) has identified iron deficiency as the most prevalent form of malnutrition in developing countries, affecting about 40% of small children and half of all pregnant women. When you consider that some caterpillars and grasshoppers have over 6 times the amount of iron as beef (Bukkens, 1997; Blasquez et al., 2012), it begins to make sense why insects are being researched for their uses in combating world hunger. Similarly, the high zinc content found in most edible insects is also of particular importance for those same demographics mentioned that are most at risk from its deficiency. In fact, other than Calcium, all of the minerals shown in the graph below are abundant in the majority of studied edible insects. Calcium, although at much lower levels than you would find in milk, is still higher in insects than in conventional meats (Bukkens, 2005).

Edible Insects, Vitamins and Minerals in Edible Insects
Vitamin and mineral content of selected edible insects in µg/100g of dry weight (data from Finke, 2002)

So in summary, the edible insects shown here are rich in essential amino acids, sometimes with more gram for gram protein than beef. They are high in Omega-3 and 6 fatty acids, as well as many vitamins and minerals. The other advantage of farming these insects is that their nutritional values can be modified, to a certain degree, by providing them with different food sources (Anderson, 2000). If you are interested in finding out more on the nutritional content of edible insects, have a read of the section on Nutrition from the 2013 UN report (pdf link) as there are lots more data from a range of studies to bolster what you have seen here.

Anderson, S. J. (2000). Increasing calcium levels in cultured insects. Zoo Biology, 19(1), 1-9.

Blásquez, J. R. E., Moreno, J. M. P., & Camacho, V. H. M. (2012). Could Grasshoppers Be a Nutritive Meal?. Food and Nutrition Sciences, 3, 164.

Bukkens, S. G. (1997). The nutritional value of edible insects. Ecology of Food and Nutrition, 36(2-4), 287-319.

Bukkens, S. G. (2005). Insects in the human diet: nutritional aspects. In: M.G. Paoletti, ed. Ecological implications of minilivestock; role of rodents, frogs, snails, and insects for sustainable development, pp. 545–577. New Hampshire, Science Publishers.

FAO (2012). Composition database for Biodiversity Version 2, BioFoodComp2. (available at www.fao.org/infoods/infoods/tables-and-databases/en/).

FAO/WHO (2001). Human Vitamin and Mineral Requirements. Report of a Joint FAO/WHO Expert Consultation, Bangkok, Thailand. Food and Nutrition Division, FAO Rome.

Finke, M. D. (2002). Complete nutrient composition of commercially raised invertebrates used as food for insectivores. Zoo Biology, 21(3), 269-285.

Ghaly, A. E., & Alkoaik, F. N. (2009). The yellow mealworm as a novel source of protein. American Journal of Agricultural and Biological Sciences, 4(4), 319.

Wagner, I., & Musso, H. (1983). New naturally occurring amino acids. Angewandte Chemie International Edition in English, 22(11), 816-828.

WHO/FAO/UNU (2007). Protein and amino acid requirements in human nutrition. World Health Organization technical report series, (935), 1.

Van Huis, A., Van Itterbeeck, J., Klunder, H., Mertens, E., Halloran, A., Muir, G., & Vantomme, P. (2013). Edible insects: future prospects for food and feed security (No. 171, p. 187). Food and agriculture organization of the United nations (FAO).