FAO has considered insects as food since 2003 and is promoting consumption of insects (entomophagy) in the Western world because of the possibilities for sustainable production it offers. Insects as food are considered to leave smaller ecological footprints than conventional livestock (beef, pigs, and poultry) regarding feed, land and water needs, as well as greenhouse gas and ammonia emissions. As an example regarding water, taken from a recent TV documentary, if a family of four people got their protein need from insects one day a week instead of from conventional livestock, over a year they would save the planet about a million Liters of water. This is in agreement with figures above. One of the main reasons that insects for food in general have such positive environmental properties is that they are cold-blooded and thus use no energy to maintain their body temperature, in contrast to mammals (beef, pig) and birds (poultry), so their feed conversion is considerably more effective than that of conventional livestock. However, differences in feed conversion may also have other reasons, and are complicated to explain, as discussed in a recent review of Life Cycle Assessments of edible insects [9]. In addition, insects can be reared on organic side streams. For example, mealworms can recycle organic residues into high-quality potential feed rich in energy, protein and fat. Insects as food are generally considered as healthy, nutritious alternatives to conventional meats such as chicken, pork, and beef. They are rich in protein, 40-60% of dry matter, with content of essential amino acids similar to beef and soy. Unsaturated fat content is 10-30% of dry matter, and they are high in calcium, iron and zinc. However, there are significant differences depending on insect species, rearing method and feed, etc. .
