How much water do you drink a day? Do you drink half your body weight in ounces a day? If not, you may not be drinking enough water for your body. I found this out personally a while back and started drinking half my body weight in ounces a day and I noticed many of the health related issues I was experiencing went away. So if you think you may not be drinking enough water, first visit your doctor and get a physical. Then ask your doctor if drinking half your body weight in ounces a day, which for most people would be around 8 glasses a day would help you out.