I think so, yes. I suffered anorexia and starvation eating disorders for many, many years, and found that pain sensitivity was higher than it is now. When your body is starving, cortisol levels go up, the flight-fight response is triggered, so is hypervigilance because your body wants you to go get food. Food in many ways is 'grounding'. When you regain weight to what is your biological set point (the weight at which your body feels most comfortable and functions the best), your cortisol and adrenalin go down again because the 'emergency' is over. So yes, your nervous system is on high alert and pumped full of anxiety producing hormones because it feels you are in danger, it's protecting you. As we know, it's the nervous system being constantly in a heightened state of arousal that triggers pain or makes us more aware of pain. If you don't feel you can regain weight on your own, seek help with a dietician.