1 In general, the total dissolved solids concentration is the sum of the cations (positively charged) and anions (negatively charged) ions in the water.  Parts per Million (ppm) is the weight-to-weight ratio of any ion to water.
If you refrigerate the rice, and you want to eat it cold, its perfectly fine. People eat cold rice salads all the time. Cold rice pudding is fine. Its just sitting around at room temperature that is the problem.
You can eat before going to bed but its up to you. Its not something you have to do. It is probably best not to eat immediately before bed as the stomach needs time to break dâ¦own the contents. You may find it difficult to get to sleep if you are on a full stomach. The same goes for fluids although a hot milky drink is supposed to help you get to sleep!