Guide to Food and Drink
1. If you have food, eat it.
2. If you have drink, drink it.
Food and drink do multiple things in the game, but the main thing they do is to increase one or multiple areas of your stat pool. The more you eat and drink, the better off you'll be on the battlefield. And you can eat and drink more than one item. If you open your character sheet (ctrl+C) you'll see you have an area dedicated to showing how "full" you are showing a bar for food and a bar for drink. You can eat and drink until those pools are filled up and the benefits from the food and drink stack.
So, if you have five drinks that add 30 points each to your Mind Pool, you could effectively drink all five and add 150 points to your mind pool, if those five drinks don't max out your drink bar. You can also eat food concurrently to add even further benefits.
Food is possibly one of the most diverse crafting professions in the game as it uses nearly every element available in game from the obvious materials like fruits, vegetables, grains, water and meat to less obvious like metals for cups and some explosive gasses used in making some alcoholic drinks in higher tier chef trees.
If you have any questions about food in game, please do not hesitate to ask.