I have never seen the alchemy skill meter rise whilst eating alchemy ingredients. But in the manual it says you can increase the alchemy skill by eating them.

It has raised it a skill point for me.

Hmmmm I didn't know this, thank you xD

Weird, just tried again and nothing. My alchemy stat is between 20 and 21. I ate 20 mudcrab chitins, and 10 thistle branches, and the stat indicator stayed in the exact same place.

Page 16 of the manual: "You raise your Alchemy skill by eating ingredients and creating potions and poisons."

Perhaps they mean only the first time you eat an ingredient, i.e. when you discover its first property?

I would think eating an ingredient would raise it, but it doesn't for me.
Using a soul gem raises enchant, i think.

I know that eating ingredients raises alchemy very slowly for me. The best way is to make potions.

Ahh so the increase is small.

I take it it only does so for discovering effects. Its done that way so you dont buy/collect hundreds ofplants and just eat them and be an uber alchemist.