Ready to do a fasting test, what are the requirements for the first few days? 1, the first few days can be a light diet, do not drink, do not eat spicy food, rest well. Avoid foods that cause high uric acid. 2, fasting is generally twelve to is fourteen hours. 3, morning fasting 8 to 10 o’clock examination is appropriate. 4, the day of the examination can brush your teeth, do not drink, or a small amount of water, do not eat food.