Unofficial SurvivalUO Wiki

Survival UO is different than any other place as Hunger and Thirst play a vital role in your gaming experience. Let’s look at some of these things.
When you start the game, you will have 40 points in Hunger and Thirst. This is a temporary boost to allow players to earn a little money to buy some Milk or Water from a vendor to allow you to drink, and gather some free food from the East side of New Haven in the form of pumpkins.
Over time your Hunger and Thirst will decrease and eventually you will have to eat and drink to keep your gains alive.

• Unordered List ItemWhen you are in the range of 16 or more Hunger and Thirst you are at your optimal gains.
  
• When you are between 11 and 15 in Hunger OR Thirst you will drop in gain rate and you will notice a slow in gains from being over 16 points.
  
• When you are between 6 and 10 in Hunger OR Thirst you will drop in gain rate and you will notice a further slowing in gains from being between 11 and 15.
  
• When you are between 1 and 5 in Hunger OR Thirst you will drop in gain rate and you will notice a further slowing in gains from being between 6 and 10.
  
• When you have either Hunger or Thirst at 0 you will never gain any skill points so do not hit this range.