I am too stupid to smoke: I am unable to control at the same time the need to have cigarettes, a lighter and an ashtray. I already have trouble finding my keys. So I never smoked, but it is not because I am smart. Over the years I learned that every ten years or so, doctors find more nasty effects of smoking and more diseases secretly related to smoking.
You probably think that the people who make a business of producing and selling cigarettes think that somebody has to do it anyway. But it is not what they do: what they do is increase the level of nicotine in their cigarettes to make sure you will come back. They also change the pH of cigarettes to make sure that most of the nicotine will get to your brain, because it is how you become an addict. Do you thik it is fair practices?
It is the same thing with nutrition. Far from me the desire of condemning the producer of fast foods!
What I don't like is people who use scientific experts to make sure that the precisely calculated combination of salt/sugar and fat will reach the pleasure receptors of your brain and make of you an addict.
There are dark scientists around. Somebody should write a book about them. In the meantime, control your life, don't let anybody else sneak up on you to make money in total disregard of the value of your life.