[uhtred]

Their mother's milk, during infancy. No mammals other than humans drink milk after infancy, and humans have only been doing that for a few thousand years. I'm sure there's links to evidence I can find but I'm not going to waste my time as it's common sense.

[melq]

If its healthy during infancy why would it be unhealthy during adulthood?

[uhtred]

Because the average adult doesn't need such a high concentration of fat and calories in a single drink / bowl of cereal / piece of cheese etc. If it was healthy and natural you'd be drinking your mother's milk as an adult, but I'm sure you aren't.

[melq]

>Because the average adult doesn’t need ...

This doesn’t mean consuming a moderate amount of milk is somehow unhealthy.

[bluGill]

Because for species other than humans the ability to digest milk is lost when they become an adult. This genetic adaptation changing everything.