gained 3.5 lbs in 3 days?!?

Sodium isn't the only indicator for water retention; rapid increase in carbohydrates will cause it too. Did you log your intake bc your assumption maybe off on how bad it was and may take a few days. Also, no need to eat less than 1200 cals to make up for it, just move on. People have a tendacy to binge more do to ups and downs like that.

Don't panic. Take a week of sensible eating and exercise and see if its still there.

I would watch your food triggers. Nicotine was a natural hungry suppressant. Now you that you quit, your hungry button has to reset. Don't be suprised if you gain more than just the 3 pounds. Average weight gain is 9 pounds for people who quit (not saying this to freak you out just want you to be prepared lol). That being said, your body weight fluctuates just as people have said.

I quit on Dec. 21. And have lost 7 pounds since then. Personally, I have found that the way MFP works, doesn't work for me. But, instead the TDEE/BMR way works. You might be the opposite, but remember you can do this. Quitting is great! And well done for doing it! But, remember....gaining a few pounds is better than still smoking.

OH, btw....I suggest you trying foods you never liked before. After a month your taste buds start to clear and you will freak out over the wonderful tastes you never knew were out there!

hormonal fluctuations may b.......

Don't beat yourself up. You have to allow yourself some leg room for the changes that are going to happen to you (good OR bad) and understand that it's not an overnight process with losing weight, and that it will even STAY the same throughout the course of your journey. I've gained weight since starting mine and have been at "0." It may take longer than you want, but as long as you know that what you are doing is right, then you are ok and will BE ok. You did good by quitting so your off on a good leg. Just make sure you "don't pig out" again for a while. P.S don't listen to the scale listen to your body.

Hello, don't get discouraged. Gaining weight could happen for many reasons. Water weight from having to much sodium. Too little or too many calories.. by the sounds of it you're eating to little. Your body needs at least `1200 calories a day or else it will go into starve mode and break down muscle instead of fat. If you have been working out you gain weight at first but burn fat due to muscle build. I hope this helps, and good luck

This post is SUCH A CONTRADICTION! You just said her body is in starvation mode, therefore her body is breaking down muscle instead of fat and yet then you say because she has been working out she is gaining weight but burning fat due to muscle build[ing] or an increase in muscle mass.

Your body doesn't start to break down muscle instead of fat because of the joke that is starvation mode. Eating in a deficit will cause loss of LBM (lean body mass, aka MUSCLE) no matter what, however you can help minimize that loss of LBM with eating enough protein and also with weightlifting. While I agree that 1200 is probably too low especially with the exercise the OP mentioned its not a magic number and there are so many other variables that could be affecting her results. A lot of times people underestimate food, overestimate calorie burns, aren't consistent with logging, eat a few times a week at their maintenance calorie intake, snack, and without knowing her stats or true activity level, its hard to make helpful calorie goal recommendations.

OP, if you are looking for advice beyond what has been given (stop weighing so frequently and the realization that daily weight fluctuations can be relatively large at times due to things other than true weight gain) it would be helpful if you opened up your diary. If not, I hope the good points that were mentioned helped you out and that you reach your goals in a healthy and sustainable way!