Been low carbing for about 2 weeks and I have a constant headache. Is there anything that can be done? I am assuming it is a reaction to not having sugar but also I am so tired all the time. Even though I was told I don't have to count calories, I have been anyway, and I know I am eating between 1500-1600 a day so it isn't like I am starving myself. Anyway, just wondered how long the detox period lasts.