|Adventuring level required|
to see full regen effect
Food and drink are necessary for efficient progress in Norrath. Without food, your Health will regenerate very slowly after a fight. Without drink, your Power will regenerate equally slowly. This will increase your downtime between fights, and slow your progress.
Food increases the amount of Health you regain when out of combat. Beverages increase the amount of Power you regain when out of combat. Different foods and beverages provide different amounts of Health or Power regained, depending on the level of the food or beverage.
You must also be of an appropriate adventuring level to gain the full effect of the regen provided by the food or beverage. For example, Sweet Onion Omelet is a level 30 food item, and will provide 53 points of Health regained per "tick" out of combat. However, if your adventuring level is 10 or lower, you will only get 10 points of Health regained per tick out of combat. If your adventuring level is 11-20, you will get 28 points of Health regained per tick.
On the other hand, if your adventuring level is far above the item level of the food or beverage, you don't get any additional regeneration. If you are level 70, the Sweet Onion Omelet will still only provide 53 points of Health regained per tick out of combat.
Therefore, it is most efficient to use food or drink that is appropriate for your level. Low-level characters will not get any extra benefit from using high-level food, and high-level characters will have increased downtime from using low-level food.
Some food and drink will provide bonuses to your attributes, such as Strength or Intelligence. Like the Health and Power regen, you will not see the full bonus until you reach a certain level. Unlike the Health and Power regen, however, it's not an all-or-nothing proposition.
For example: Level 30 food and drink items which provide a bonus will provide a full bonus of +4.6 points to the affected attributes. To get this bonus in full, your adventuring level must also be 30 (or higher). If your adventuring level is lower, you will still get a bonus, but not the full 4.6 points. At level 21, you might see only a +3.3 point bonus to the attributes, while at level 25 you might see a +3.8 point bonus.
To get the full effect of any stat bonus from food or drink, your adventuring level must equal the item level of the food or drink.