1: You will not put on weight if you stick to your diet and exercise regime. The reason why people gain weight when they quit smoking is because they need something to put in their mouth - instead of cigarettes, it's often snack foods! You need to be aware of this, and having some gum/sugar free lollies on hand is a good idea.
For more tips, call the quitline or check out their website.
2: BMI is not accurate, it is a guide. The BMI is OVERESTIMATED
. This means, that because of increased muscle mass, your BMI may say you are overweight when in fact you are healthy. For athletes/body builders, BMI is pretty useless, and they go off body fat percentage to determine how healthy they are.
The BMI scale is most useful for the underweight portion, because it OVERestimates. So, if your BMI is 20 (just on the lowest limit of healthy), but you have a lot of muscle, you are probably actually UNDERweight. If you are underweight according to the BMI, you are definitely UNDERweight and you should not lose any more weight. If you feel you need muscle definition, by all means you should be exercising/doing weights and you should be checking your body fat percentage, but you should NOT be aiming to lose any weight - in fact you should be gaining weight once you start gaining muscle.
It is NEVER healthy to be underweight according to the BMI, but it MAY be healthy to be overweight according to BMI if you have lots of muscle. Make sense?
3. Never got close to goal weight, so I can't really help with this one