[pharrington]

The symptoms you're describing are also primary symptoms of dehydration.

A more reliable exploration would be, after diligently logging your food and drink intake (with time and quantities) along with your physical feelings for a couple months, add a daily regime of a specific amount of pure MSG. Start small, and increase the MSG intake until you start feeling adverse symptoms. Assuming symptoms manifest, then increase your daily hydration levels (obviously not to the point of giving yourself hyperhydration) and note when/if the adverse symptoms previously noted diminish.