Unfortunately Sodium is sodium, any doctor will tell you if you are required to have less than 1000mg (or whatever the measurement is) of sodium a day celery is definitely out. So whilst it might be fiberous and what not the sodium content would be just as much an issue (if that concerned you) as weet-bix. Another interesting fact about sodium is that in salt its only 40% sodium and 60% chloride and as humans we do need a certain percentage of sodium in our diet. Sodium deficiency can be just as bad for us as too much. So its important to note that moderation is the key with any foods. Just as overeating some of the healthiest foods for us can make us sick so can having too little of things like fat, sugar and salt. They all have their place. Obviously processed foods are not a necessity but even things like the raw diet and wholefood diet can make people sick too. This happened to my SIL who ended up with no periods and malnutrition from being on a raw food diet. Which is quite interesting. She still eats quite healthily but she is no way near as hard on herself, and now her body has returned to normal.