"In an artificial life simulation where survival required energy but giving birth had no energy cost, one species evolved a sedentary lifestyle that consisted mostly of mating in order to produce new children which could be eaten. Children could also be used as mates to produce more edible children."

Very suspicious, but ingenious... Suitable for some, very few, lazy hebephiles who do not like exercise at all.

But of course this works only if giving birth does not require energy, and if the children are fertile already.

http://digg.com/2018/ai-neural-network-exploits