system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: In survival/apocalyptic movies, people can survive by just eating insects alone. Is this true in real life?
gpt
People eat insects, and they can provide some useful calories and protein.

But no human society has survived using insects as a major source of its calories, and for a very good reason.  The amount of calories you gain by eating an insect is very small in proportion to the effort it takes to capture or cultivate it.  In many cases it will burn more calories to harvest and prepare an insect for food than it provides in calories.  

So if you are going to spend time gathering a food resource, it's a very poor choice.  But if you are starving and see an insect as a target of opportunity, eat it.