There is little disagreement that eight full glasses of water (64 ounces) per day are required for good health. There is some disagreement about whether some part of that might come from other clear liquids. Many people find that they lose best when taking in up to half their weight number in ounces of water each day - not counting other liquids. In other words, if you weigh 200 pounds, you would aim for 100 ounces per day.