Hi pferde01,
Sarahinparis wrote a great post here giving multiple explanations for your weight gain/experience you posted about here...so I won't repeat any of them.
But she is so right about things like beer and cookies wreaking havoc because Atkins is a metabolic diet....and truly is a double-edged sword in that it can work fabulous if you stick to plan but can cause weight gain if you add in things not on the plan. It's very critical to stick to plan, IMO.
I think it's totally fine to go off plan if you've planned for that and know the consequences and factor that in. I stay on plan simply because I don't want to have to go through those 2-3 days again where I'm hungry due to my body again having to use up the stored sugar (I think it's glucagen, not sure if that's the exact term).....until my body goes back into ketosis again. Unless I specifically planned for this....it would cause me to get frustrated....having wasted several days....having to invest time again to go back into ketosis....and to have even possibly gained for a few days....just too frustrating for me to risk going off plan....just out of weakness.
Like I said.....a planned going off plan is different. Events happen in life that are out of our control and we have to deal with them and factor these in. But repeated episodes of going off plan....just sporadically and not specifically planned for....can stall and frustrate us.
If I'm understanding your post correctly....what you're saying is that it concerned you that just a small change in plan would result in what you saw as a significant weight gain....right? I can actually very much relate to this....as I've been there myself. It made me think....what good is this diet if just a small variation is gonna cause this amount of gain?
BUT.....I managed to maintain my weight loss for almost 15 years the last time I used Atkins. It definitely is a plan that can work for life. However.....yes, I could eat cookies....but had to be very careful about the additional carbs I ate. Had I allowed myself to start having these things daily, I would surely have inched back up and gained it all back. I made a rule that if I gained 5 lbs., I went back on induction and lost it. This was the price I paid for allowing things like cookies too often.
If you stick to plan, over time you will see that it is definitely a diet that can work for life. You gain a lot of understanding, over time, as you stick with it. You do have to be rather rigid in order to maintain consistent weight loss...but when you get to goal....you can have a great deal more variety in your diet as long as you're careful. I mean, let's face it....if we're not careful, we'll gain back the weight no matter what diet we used to get to goal.
The worst thing you can do is to allow an episode of going off plan to result in an off-plan spiral. Just get back on plan......and stay away from the beer.