But certainly a trend and perhaps an excuse to tax and track people more. Still without such laws we would not of got a beer like this: https://www.brewdog.com/item/61/BrewDog/Nanny-State.html
Which sums things up about as well as any.
I am certain outlawing base primal urges, like the right to ingest what one desires into one's own body makes such primal urges even more favorable, often to the point of detriment to the State who then have to feverishly invent something inverse to people's actual needs like Alcohol, or bromides like Sugar to pacify their citizenry.
Taxing soft drinks is no different. Soft drinks are making the whole population (not just children) obese, so discouraging people from consuming them improves public health.
This isn't a parenting issue any more than having your local health department do free STD screenings is. It's a public health issue, which affects people of ALL ages. It's entirely appropriate for the government (at whatever level) to enact policies to try to improve public health, whether it's positive (STD testing, free condoms) or punitive (taxes on undesirable things). It's entirely valid for a government to have extra taxes on things which cause disproportionate costs to society, such as alcohol, cigarettes, and soft drinks, and to attempt to encourage positive behavior (such as how many US states have lower or zero sales taxes on (some) groceries, in order to reduce the burden on the poor and encourage people to prepare their own low-cost food instead of eating fast food).
If you want to complain about the State interfering with parenting and being a nanny, the laws in some US states basically forcing parents to be "helicopter parents" and forbidding children from walking around outside without adult supervision should be your target.
Fundamentally, my belief is that the government has a responsibility to provide for the general welfare of society, but in order to do so it needs to use evidence-based thinking. It also needs to balance this responsibility with the human rights of its citizens and the desire for freedom. There's mountains of evidence that tobacco is extremely bad for public health, and there's plenty of evidence that alcohol is also bad (except here, it seems to be OK and harmless in small quantities, like a glass of wine with dinner, but is a real problem when someone is addicted or drinks and drives), so regulating and taxing these things is justifiable. There's plenty of evidence now that soft drinks are associated with obesity, so the same applies here. There's zero evidence that having kids walk around by themselves at the age of ~8-10 is associated with a statistically significant risk of kidnapping, so there's no justification for the helicopter parent laws. And there's zero evidence that marijuana is as dangerous as cocaine or heroin, or any more dangerous than alcohol or tobacco, so there's no justification for criminalizing it instead of just regulating it the way we do those two things.