Well I don't eat ready meals at all, so what is actually classed as processed foods? I eat potato's (not chips), brown rice, wholemeal pasta, brown bread, the only frozen food is chicken and fish.
I always have cravings of putting salt on my meals, which to me means my body needs sodium?
Bread is a processed food and is a source of salt (the #1 source in American diets). Pasta, potatoes and rice are normally prepared in salted water. Still, if that's the way you're eating, you may very well need more salt. Doing some arithmetic, if most people get twice as much as the need, and most people get 3/4 from processed foods, then those people that don't eat processed foods likely only get about half the salt that they need. Sodium deficiency can cause seizures and coma. The body will tell you very clearly when it need more. That's what the cravings are. This is also why salt was so highly prized in ancient times.
On the other hand, your cravings may be a result or a dysfunctional body feedback system. If you have high blood pressure, you should consider this a possibility.