Unexplained weight loss?

I recently found out I was gluten intolerant. I was not diagnosed but I just stopped eating all bread and gluten products and my digestive problems went away. As a result I have completely stopped eating gluten. This was a little more than a month ago. Since then, I have gone from about 164 pounds to 157.5 pounds without any exercize at all. My appetite has not changed, I still have energy, and no other changes other than a more normal digestive system. I always hear about hoe unexplained weight loss, or weight loss with no exercize is a concern. My question is, given these cirstances, should I be concerned. Would the dietary change cause the weight loss? And is this cinsidered rapid or extreme weight loss? Thank you.