Seven out of 10 millennials are now expected to be “overweight or obese” by their late 30s – compared with an already alarming half of baby-boomers. The well-documented burden on the NHS from type 2 diabetes alone will be crippling. Already only Iceland and Malta are fatter in western Europe. It is therefore a legitimate concern of the state. Yet the state is dodging the issue. The lobbies – Big Food and Big Drink – are too powerful.

Obesity is caused not so much by an unhealthy “lifestyle” or lack of exercise. It is caused by unhealthy eating and drinking, as lung cancer and respiratory illness were caused by smoking. We tackled that crisis. Steady declines in lung diseases over 40 years can be directly related to less smoking, related to tougher regulation. In the US, men stopped smoking faster than women, and fewer died.

There is now no argument. Obesity should be treated like a national pandemic. The sugar industry loves to deflect, arguing that responsibility lies with schools and parents. It does, and it is absurd that advertising should still be permitted showing happy families tucking in to vast helpings of “bad” food – as it was when tobacco was advertised as having sex appeal. It is irresponsible to advertise products to children, not least during popular programmes, that we know are going to kill them. It is preposterous that fast food outlets should be allowed near schools.

But the big challenge is price. Here the remedies are familiar. High-sugar drinks and hyper-processed manufactured foods should be severely taxed, as were cigarettes. Alcohol should be more taxed than now. School food should be monitored for levels of fat, flour and sugar. Packages should be labelled accordingly. This is nudge government. None of it infringes individual liberty. The only curb is on business’s freedom to abuse other people’s bodies. Obesity is a far greater threat to personal health than marijuana, yet we promote the one and criminalise the other.

The problem is political. When in 2016 the Cameron government proposed a 20% sugar tax, howls from the food and drink industry brought about a humiliating capitulation. When obesity was proposed as a compulsory subject in school, teachers protested at being expected to lecture parents and children about their appearance. Sooner or later these hesitancies will end. It cannot be soon enough. Within a decade, seven out of 10 millennials could be overweight or obese. That has to be absurd.

• Simon Jenkins is a Guardian columnist