Hmmmmm
How exactly do 2 chocolate chip cookies ruin a diet - if you enjoy them- make them work into your plan...
Work it in.
If we are talking 2 X 2 inch standard chocolate chip cookies were looking at 48 calories each. Double that if they are huge. Cut out 100-200 calories of something else, (half your rice at dinner, one of your snacks, etc) and you just saved yourself a hell of a lot of jogging my friend....

Hardly ruination!
Sometimes those weak moments can help. We are not machines, I work "with" my weakness, not against them. I have been very successfully following the "free day" system of weight loss and not only broke a long and nasty plateau, but I also have been steadily dropping 2 pound+ a week for almost 2 months now. Here is what I ate this weekend (because my free day sort of turned into 2...)
6 Baozi (steamed chinese buns) about 500 calories
4 or 5 pieces of fruit - 300-400 calories
Yummy fried noodles for lunch - probably LOTS!! of calories
A nice big coffee flavored icre cream - *Shudder*
white rice, and several stir fried dishes in a restaurant - Oh my, who knows...
A beer with dinner - 650ml of pure yummy
a couple more of them big beers back home - that was fun
And that was just saturday. Sunday wasnt quite so bad, but it werent perfect!!!
When I jumped on the scale it went from 255 on friday, to 264 on monday. I laughed! I am not even kidding, I laughed! I knew most of that weight was from the alcohol and salt playing havok on my system, and i KNEW it would be gone by later in the week. Here it is Weds, and I am down again to 253, 2 pounds less than last week. And heres the kicker, I exercise less. I only do taebo once a week, weight train once a week and do my power stretching and strengthening periodically in the morning.
But I am still losing weight.....
Mind you I do run home from work everyday and walk for 30 minutes at lunch time regularly. I dont consider that exercise though, more transportation.
I honestly believe that by giving myself these "free days" then sticking to a very controlled diet the rest of the time, I am kick starting my metabolism every weekend and not allowing it to become accustomed to my lower calorie eating through the week.
Now, of course this may not be the case with everyone, it just appears to be working for me. Free days, if not kept in check can easily turn into free "weeks". The point I am trying to make however, is there is no real failure in this game, unless you stop trying altogether. Taking a misstep is not the end of the world. if that were the case I would be dooming myself to failure every single solitary weekend! Yet I now have my goal in site, feeling better than ever before.
For many of us, myself included, this is the single hardest thing we have ever had to do in our entire lives. As a teacher I would never hurt or punish someone learning something new if they made a mistake, yet I could so easily do it to myself. Don't fall in to that trap, took me almost 40 years to find my way out again.
sirant