8 cups of fluid a day is recommended. Water does tend to curb the appetite, but if you are feeling hungry, that is your body telling you that you need to eat. Depriving your body of energy and needed nutrients is counterproductive to good health.
One way that dehydration can mask itself is by producing a hungry feeling. So if you are not properly hydrating yourself you may feel hungry. If you feel hungry try drinking a glass of water. If you are still hungry, it's time to eat.