· There has been so much fuss about obesity that it seems increasingly likely that it will be included in some shape or form in the GP contract, much to my dismay. Essentially this would mean that doctors would be asked to record the weight of patients and offer advice about weight loss if appropriate. It might be fair enough if the patient comes in asking for advice about weight, or if the medical problem is related to it, but do I want to do nagging professionally? No.

I didn't realise that I felt quite as strongly about this until I was at the hairdresser's, my son in the chair. "You get your hair done here, don't you?" said the hairdresser. I agreed. "When did you last get it done?" Wee while ago. There was a low sigh. "And are you happy with the style?" Yeah, I said, not having looked in a mirror for days. "Maybe I could offer you a bit of advice. How do you usually style it?" Erm ... She looked at me with heroic amounts of sympathy and addressed me in a kindly, confidential tone. "Are you struggling a bit with it?" It's called opportunistic advice, aka health policing, and it makes you feel really ugly, and completely disinclined to ever go back there again.

· A fag in the pub or after-dinner cigars: these shall soon be hazy memories. Smoking in public is now high on the agenda to be banned. No doubt fierce argument from dissenters, led by Forest, the pro-choice group, will follow: its online site proclaims that it is "a little taste of heaven for smokers and tolerant non-smokers!" And a very interesting site it is, keen on evidence and rightly outlining the fact that so much "scientific proof" is just a variation on the degree of certainty. Stroll through their web pages and they denounce many health scares, such as hair dye or electricity pylons causing cancer - and all quite reasonably. The language is of libertarianism and tolerance, written by adults who say that they understand the risks and have decided to seek their pleasure in cigarettes. Amen to that: I would even overlook their funding from the tobacco industry, for, of course, people should be allowed to do as they wish etc.

But something is missing. The idea that we all choose our poison with liberty and freedom is entirely wrong. Take a look at the figures on smoking and social class: the lower the social class, the more likely a person is to smoke. And remember John Reid last year: "What enjoyment does a 21-year-old single mother of three living in a council sink estate get? The only enjoyment sometimes they have is to have a cigarette." Always easier to let folk pay tax and smoke rather than to deal with the nitty gritty problems of inequality that led them to buy fags for their "only enjoyment" in the first place. It sounds suspiciously like a let-them-eat-cake kind of argument, but with a shorter life expectancy instead of icing to top it off.

In effect, no such freedom of choice exists. My job would be easy if people chose smoking from one of the many pleasures they had the equal choice to pursue. But if you really wanted to make the opportunity to smoke equal, then you would have to start shoving free cigarettes through nice middle-class letterboxes.

In reality, we don't have equal access to fags, and we have got so used to health scares that enormous black letters on cigarette packs warning that "SMOKING KILLS" are dismissed with the fatalism that is more rightly reserved for hair dyes and electricity pylons. It's not just smoking in public places we should be thinking about; it's why the class divide about smoking persists at all.

· The writer is a GP based in Glasgow.