If you can drop 100+ lbs by smoking half a pack a day, I guarantee you'll be a lot healthier overall. Not saying you actually _would_ lose all that weight, but it's not like it's a binary between "smoking" and "not smoking". Frequency and amount matters, but the it's pretty much impossible to approach the subject in our society with any sort of objectivity or science.

Sure, and amount of extra weight matters too. But there are probably better ways to lose it regardless..