Yes, adjustments need to be made. After years of living with an artificially elevated metabolic rate due to nicotine, you are now returning to your 'real' metabolic rate.
The good news is that the nicotine raised your metabolism by maybe 10%, so you're talking about an average reduction in calories burned of about 150-200 per day or so; as Mike pointed out, that should be overcome by about 30 minutes of walking (practice deep breathing while you're walking and get a bonus of helping your lungs to heal at the same time ). There is no reason for you to regain all the weight; cut back a bit and exercise a little more.



Agree 110% Smoking is hurting you far more than a few extra pounds will.