That reaction is more than normal, Grad.
I am against the Atkins diet. I could talk and talk and talk about diets and nutrition, but it would be too long. All I'm saying's I had my mom lose a lot of weight without depriving her of pretty much anything. What I did was improve, regularize and balance her diet itself. Our organism are conceived to only store food and burn it, but storing in for fear of a famine is what our evolution has taught our body to do. It hasn't changed yet. So once you WRONGLY take carbs suddenly off your diet then your body loses weight immediately, but there are two consequences:
1. Several values, specially in women, start to go up and down or simply down. Hormons especially. That is bad.
2. Once your body has verified, much to its shock, that there has been a sudden and large lack of carbohydrates, it will modify its metabolism in such a way that it learns to significantly slow down the burning process. In other words, your metabolism slows down like a snail. That means whatever you eat afterward, and above all all the carbs that you will re-insert in your diet (be it after 4 weeks or 2 months) will be stored and hardly be burned again. At that point if you try the harsh diet one more time, it will be harder for you to lose weight again, and then a cycle takes place. It's the famous yo-yo effect. This is extremely counterproductive because in the end, after a few times, you'll have to work 40 times as hard to see some results. Your body will have learned to not trust you and fearing an immediate lack of food it will do its best to convert all that it can into fats.
Of course I voted the never been on a diet thing.
Update: damn Option # 1 and the Don't diet option can overlap, I went for #1 but I shouldn't have, it seems. Oh well.
Update 2: I think I should point out my diet is the so-called Mediterranean diet, which consists of a hugely less amount of sugars, sweet drinks and greasy snacks.