Insects are a nutritious food source that can be produced more sustainably than conventional livestock. Although eating insects is common in many parts of the world, in Western cultures it is more likely to be disgusted.
Insect consumption slowly increased as the benefits became widely discussed. Over 2,000 edible species have been identified. But would incorporating insects into our diet really reduce the environmental footprint of food production, and is it possible?
Insects are rich in fat, protein and nutrients. This varies by species and life cycle stage, but the protein content of insects is often 40%-60%. Insects also provide all the essential amino acids needed for human nutrition.
Adult crickets are 65% protein by weight, which is higher than beef (23%) and tofu (8%). Insects are also rich in minerals such as copper, iron and magnesium. It is therefore not surprising that insects are eaten by humans in many parts of the world today.
Insects are much more efficient at converting their feed into energy than conventional livestock. Adult crickets and mealworm larvae need 5 to 10 times less feed than cattle to produce the same weight gain. Insects are also cold-blooded, so don’t use their metabolism for heating or cooling, which further reduces energy and food consumption.
A greater proportion of the animal can also be eaten compared to conventional livestock. Only 45% cattle and 55% of a chicken is consumed on average. For insects, the whole larva and 80% of an adult cricket can be eaten. Insects also reproduce faster than vertebrates, with several generations possible in a year.
At equal nutritional value, insect farming therefore uses a fraction of the land, energy and water used for conventional farming.
To produce one kilogram of protein, mealworm larvae emit 14kg of CO₂eqmuch less than the 500kg of CO₂eq emitted on average in beef production. To produce the same amount of protein, the culture of mealworm larvae uses 70 times less agricultural land than beef.
Plant-Based Foods Should Not Be Ignored
All food production has environmental costs. However, there are substantial variations in this area. Beef, for example, produces 100 times more greenhouse gas emissions than pea production.
Insect farming generally falls between these extremes. Although it may be less damaging to the environment than meat production, it has a higher footprint than most plant-based foods. Per kilogram of protein, pea production emits only 4kg of CO₂eqwhile tofu requires about half of the agricultural land necessary for the breeding of insects.
Whether insects are a climate-friendly food (or more) will depend on what the insect protein replaces. If insect-based foods are used to replace conventional meat, it could bring big gains. However, significant gains could also be made if plant-based alternatives are adopted.
Dietary changes can dramatically alter the environmental footprint of consumers. The average diet in the United States uses more than 10 times more land per person than the average Indian diet, mainly due to the types of food eaten.
Using insects in a circular food system
1.3 billion tons of food produced for human consumption is wasted every year. Another area where insects could prove valuable is in the production of food or animal feed from food by-products or food waste. Black soldier flies bred on by-products such as almond shells can be converted into livestock feed or farmed seafood.
However, feeding insects organic by-products requires careful management to avoid risks of chemical and microbial contamination. Several species of insects are capable of digest certain contaminants, but there is potential for harmful bioaccumulation. Manure and catering waste are therefore prohibited as food for farmed insects in Europe.
Will Europeans eat more insects?
The market for edible insects in Europe and America is growing. Despite only 10.3% of Europeans declaring that they would be willing to replace meat with insects, the edible insect market is expected to reach US$4.63 billion (£3.36 billion) by 2027.
Food acceptability may change over time. Tomatoes were considered poisonous in Britain and shunned for over 200 years. Lobsters, now an expensive delicacy, were once so plentiful in the United States that they were served to workers and prisoners and were commonly used as fertilizer and fish bait.
Lobster only became fashionable after the middle of the 18th century. Since then, its popularity has surged, with the global lobster market expected to reach $11.1 billion (£9.7 billion) by 2027.
The consumption of insects in Europe could also normalize. Western consumers are showing a growing desire to consume insect-based processed foods. Incorporating insects into familiar foods such as flour is one way to improve their acceptance.
Edible insects are not the only solution to achieving a more sustainable food system. However, they provide a nutritious and more sustainable substitute for conventional meat. Their production, flexibility and diversity mean they are likely to play an increasing role in a more circular food system.