I started Primal about 3 weeks ago. I'm trying for less than 50g of carbs in order to promote weight loss, as I need to lose about 15lbs.

This is a strange question, but I've been noticing that I'm yawning a lot. I don't feel too terribly tired, although I'm not exactly bursting with energy either. But I feel the need to yawn. A lot. I've also been very irritable.

Is this a nutritional deficiency of some sort? Any advice to sort it out?