2 weeks after starting Atkins seems kind of soon, most people don't shed hair until about 3 months after a trauma. This has to do with the basic biology of the hair growing cycle, so in this case I would wonder if something happened to the new dieter about 2 months or so earlier than Atkins to cause that.

I shed hair for a few months too, in my case I think ketosis was indeed the trigger. I can eliminate most of the other possible causes for myself. However, I think what a body percieves as a stressful event can be very individual, ranging from emotional to physical (including changing a diet). I have also been under the impression that LC can be beneficial to the thyroid in cases where low thyroid function is from imbalanced hormones and poor lifestyle and diet. At any rate my body temp has risen somewhat with LC, which would not be the case if I had become hypothyroid.