Helen Brown, a young female accountant, has had a great Friday evening. She came out with more than £50, and nearly all of it has gone on gin and tonics, Bacardi, Tia Maria and several alcopops as well as entry to a night club in north London, where she is making the most of her weekend. 'I'm going to be off my head,' she said, swaying dangerously towards a table. Her friends, much the worse for wear, fall over each other as they try to make it to the dance floor. None of them expects to see much daylight on Sunday.
The consequences of taking in 18 units of alcohol in one evening are well known to Brown and she doesn't much care. The choices she makes now, at the age of 24, will influence her health for the rest of her life - they will have an impact on her appearance, her chances of conceiving, her heart, her brain, and of course, her purse.
The big question the government will attempt to answer this week is just how far the state should intervene in questions of personal responsibility. Does it have any role at all in trying to make young women drink less, for example? Should it bring in draconian regulations against drinks manufacturers, or clubs that continue to sell booze to customers who are clearly intoxicated?
On Tuesday, the Health Secretary, John Reid, will unveil a White Paper on public health which will cover obesity, binge drinking, smoking and sexually transmitted diseases. It is a document about preventing illness, but really it is about farmore than that. It is the benchmark for how we govern the behaviour of the individual.
Nothing has illustrated the difficulties of tackling personal health more than the obesity epidemic. In the past year, there have been more than a dozen reports on the subject, with every conceivable expert group weighing into the debate. A vicious war has also broken out between consumer organisations and the food and drink industry, as it faces the threat of regulation and rules over what it sells to customers.
Many doctors have called for radical action over the obesity epidemic, a trend which has led to two-thirds of adults in Britain now falling into the overweight category, and seen the rates of obesity in children treble in a 20-year period. Professor Philip James, an international authority on the subject, has warned that, if things continue as they are, the current generation of children will die before their parents, their arteries clogged by the fatty plaque laid down by their poor diets and indolent lifestyles.
James wants to see a return to the postwar habits, which saw families eating around the table, usually a freshly cooked meal of meat and two veg. He would also advocate parents must become far stricter with their children over mealtimes, to counter the 'pester power' factor which sees overworked parents giving in to children who clamour for sweets in the supermarket.
But the message coming from the Department of Health so far has been, according to critics, muddled and confused - on the one hand threatening to get tough with the industry over labelling and, on the other, allowing Cadbury Schweppes to sponsor sports equipment in schools. The government was so baffled by the sudden media attention over fat, ministers even commissioned a think-tank this year to find out why the issue had hit the headlines.
This week will see the government's most concerted attempt so far to address those uncertainties. For the first time, a proper food labelling scheme will be introduced, with a red, orange or green light given to foods according to their nutritional status. Those with a red label, which will include chocolate, confectionery, doughnuts, and fizzy drinks, will not be allowed to advertise on children's TV.
But the devil is in the detail. What do you do with a food that is very high in fat, such as Cheddar cheese, but has lots of protein? Or raspberries, which have a high sugar content? They may end up with an orange label, but some people would see this as deeply unscientific. Jeremy Preston, director of the Food Advertising Unit, an industry-funded body, believes the new rules send the wrong message.
'It's not about foods which are good or evil, but about the amount of food you eat,' he said. 'One chocolate bar is not going to kill you, even if it has a red label. They should be educating people about balanced diets, not demonising products.'
If food is a minefield of conflicting interests, the same goes for alcohol, where consumption rates have been rising steadily in Britain over the past two decades as its pric, in real terms, has fallen. This summer, there was a series of accounts of the number of towns and cities that were becoming no-go areas on Friday and Saturday night, thanks to the squads of young men and women like Helene Brown who would be out drinking with little interest in sticking to a sensible limit.
At the same time, the government has passed a new act which will break down Britain's licensing laws, allowing pubs and clubs to open around the clock from next summer. Panic set in - the police started talking about the need for extra resources to tackle alcohol-fuelled crime and worried doctors pointed out that one-quarter of casualty patients had a drink-induced injury.
There was a crackdown on under-age drinking in pubs but then the industry itself came under pressure to do something. This weekend, the Portman Group, representing the manufacturers, started its own website to help consumers work out how much they could safely drink each week. The reality is that the people who log onto this site are least likely to be the people like Brown who are out at the weekend down the clubs.
But it is the third 'sin' in the public health debate, smoking, which has recently created the most heat. More deadly than the other two evils combined, nicotine is the substance which has caused real agony for Labour. Ministers have had to watch first Ireland and then Scotland head towards an outright ban on smoking in enclosed public places. Reid has clashed with colleagues as he refused to go down the path of a full ban. This week he will instead look at a system of banning it in bars and restaurants, unless they hold a special license to allow smoking. Reid will send a strong signal to non-smokers that the wind is blowing in their favour, but he will make clear his reservations.
'The idea that someone who has risked their life for their country, jumping out of a plane over wartime Holland, should be banned from taking the risk to their own health from a cigarette over a pint with their friends in the Royal British Legion does seem a little heavy-handed,' says one source close to him.
Tony Blair himself gave up smoking more than two decades ago on the insistence of his wife-to-be. But he is too ruthless a pragmatist to let his personal habits cloud his political judgment. He was first asked almost six years ago by his then Health Secretary, Frank Dobson, to ban smoking in public places: worried about a backlash, he refused.
It is certainly a matter of life and death, as the government's own independent Scientific Committee on Tobacco and Health will demonstrate this week when it publishes its long-overdue report on passive smoking. It is expected to argue that a quarter of lung cancers are caused by second-hand smoke, arguing that no infant, child or adult should be exposed.
Reid will argue that the real victims are the children and non-smoking partners of people who smoke at home, not in the pub - with up to a third of cot deaths now blamed on parental smoking, along with countless episodes of childhood asthma and respiratory failure. But he was badly damaged by comments he made earlier this year, when he said that smoking was one of the few comforts left to poor people - a comment that was widely criticised as being patronising and ill-informed. He was certainly right, however, to associate it with poverty, as a study by the University of Portsmouth published last week showed that the highest number of smoking-related deaths occur in the most deprived regions.
The one area where the government might find it easiest to make a difference lies, paradoxically, in bedroom behaviour. The explosion in sexually transmitted diseases in particular threatens not just lives and love affairs but NHS budgets: The government's own expert advisers estimate newly diagnosed cases of HIV/Aids are now costing £90 million a year.
One easily achievable measure is to set waiting lists for the clinics, which have been overwhelmed by demand for tests yet are unable to offer them quickly because they have been starved of cash. The more difficult area is whether there should now be a campaign to warn today's 15-year-olds of the dangers of sex. Rates of gonorrhoea, syphilis and chlamydia have soared, largely because condom use is low. When the first Aids TV campaign ads featuring tombstones were aired in the late Eighties, people were shocked into buying condoms but that message appears to have been forgotten.
Anna Coote, research fellow of the King's Fund think-tank which will next week publish an analysis of past public health interventions, argues ministers are unnecessarily worried about pushing the public towards healthier living. She points out that voters adapt remarkably speedily to controversial health measures, from drink-drive limits to new vaccinations.
'There's a great public outcry, and then the measure's introduced and it all quietens down and within a couple of years people are saying, "How did we ever manage without that?"' she says. 'The government is scaring itself with ghost stories: nobody is accusing them of being a nanny state except themselves.'
Nineteenth-century medicine was remarkable for its pioneering work on public health. The middle classes, outraged by the plethora of infectious diseases and death on their doorstep, demanded that proper housing be built and slums cleared. Clean water and sanitation were introduced, diseases identified, and vaccines developed to eliminate the worst infections. Priorities have changed. The dangers don't come from the person coughing next to you, but from your own lack of willpower when it comes to food, exercise or drink.
It is childhood that really worries policy-makers, because the habits laid down in the first five years of life, in terms of food and activity, will largely govern children's health later on. Reid has accepted that strict measures need to be taken to protect children not yet old enough to make informed choices, and he has been particularly appalled by the cheap food given in school dinners and packed lunches.
Health industry advocates say that the really big step that would help everyone, young and old, is to encourage more exercise - a very difficult area. The government will be encouraging companies to set up a system of tax breaks for those who cycle to work, and it is putting this into action by giving more than half a million civil servants an entitlement to a free bicycle. There will also be an army of lifestyle coaches brought in to the NHS to offer fitness sessions to those who need to lose weight.
Professor Ken Fox, a social psychologist from the University of Bristol, who has been instrumental in helping ministers try to frame an activity policy, said: 'Walking and cycling are the two activities which would make a fundamental difference to everyone's lives. But that means making it a crucial part of a transport policy, and designing streets that are walkable, and putting in cycle routes to schools, and I'm really worried that won't happen.'
Helene did not say whether she had a bike. She was too busy thinking about her next alcopop. And that, for the government, is the big problem: how to change her mind without hitting her over the head with a sledgehammer.
