I think taxation on the basis of health concerns is wrong. Once a tax has been established and the revenues are willing to go to the state's coffers, why should the system want to abolish it? Everyone benefits from illness in such a moment. Our entire system works on the basis of economic equations. Tax as a punishment: Who really cares? Taxes on tobacco, alcohol and other stimulants are only a nice source of income, but they are not a real barrier to consumption. People would buy unhealthy things even if they were made more expensive and might even prefer to do without healthy things, especially if they have little money. From an economic point of view this is a smart move, but from a systemic point of view it is more likely to be the preservation of what you are used to consuming and finding in the choice of goods than a reduction. The rethinking in the direction of awareness is not the result of higher costs, but rather of social ostracism. Smokers are second-class people (not my view) because they are considered undisciplined, addicted and also unattractive.
Punishment or reward in the form of tax penalties or benefits is a weak means because it distorts the authenticity of the situation. From my point of view, only permanent education and rethinking can achieve this. But anyone who wants to eat an unhealthy diet because he thinks he has too little money or unconsciously wants to compensate something should be allowed to do so with impunity. Fortunately, humanity consists of very heterogeneous individuals, groups and interests that are multi-faceted. After all, we do not have two, but countless interests, groups and individuals who make different statements and pursue different lifestyles. Unhealthy food may at some point in the future be just as outlawed as smoking. And yet there will still be smokers, just like unhealthy eaters.

From my personal point of view, the price of food has never stopped me from buying it. Here my sense of taste dominates, my desire for what I want to eat. Fortunately, I have never had a penchant for fast food. It doesn't taste good to me and I don't like the concept either. Why so many people eat fast food is a mystery to me. It is boring there, it stinks, there is no surprise, no atmosphere, no aesthetics, nothing that would attract me. I wonder how the fast food chains manage to find people who want to run the franchise. How much creativity and design freedom do you have to give up? Earning money in a battery is just as boring as eating battery food. But that's just my own opinion, it certainly doesn't reflect a general picture.

Another aspect: food depends on the cooking culture. Those who don't have a real cooking and eating culture at home will cook less and eat less together. This is connected with single households and single parents. The common meal time is dying out and therefore cooking is a rare act in the kitchens of individual households. The social component of food is less important when there is no one to eat with. Basically, taxation would be a kind of punishment for the lifestyle of a cook-less culture. But the fact that so many people live in single households and not with other people under one roof is an expression of an industrial society that can afford people to live alone. Living alone in agricultural communities is unthinkable. Also the argument of the poor with many children does not work, because there are probably many more childless and singles opposite them. But that is mere speculation on my part.