Misfortune has its funny side, and doctors see a lot of it. But a patient who hears that he faces salami surgery will not see the joke

"Hello sir. You don't mind if I teach the students on you, do you? Jolly good. Now, this chap's got peripheral vascular disease and today I'm going to chop his toes off. Of course, that'll only be a temporary solution. He'll be back with gangrene in a few months and I'll have to take off half the foot. Then the whole foot, the lower leg and gradually over the course of the next few years I'll be working my way up to the knee and above. I call it salami surgery. Any questions?" I've got one. Do consultant surgeons really still speak to patients like that in 1997, or have I just made it all up for a cheap, sensationalist, column-opening? Well, I wasn't there at the time but I'm reliably informed by a medical student that this particular incident of bedside teaching really did take place. Last week.

Shortly afterwards in the doctors' mess, the same student stumbled across some junior surgeons discussing their career options. "Do you put wife before knife, or knife before wife?" "Knife." "Before wife?" "Of course." "Absolutely." When she pointed out that comparing a life soul-mate unfavourably with a scalpel was a tad disrespectful, she was treated with derision. "Oh no, we've got another lefty lesbian on our hands." I could go on but you get the picture. There are still plenty of surgeons out there who make Martin Clunes seem like Germaine Greer. And they're proud of it.

To be fair, you do need to make enormous personal sacrifices to reach the top in surgery, and brainless hectoring is one way of coping with a very stressful job. Likewise, laughing at misfortune. When I asked a group of medical students whether it was possible to have a sick "salami surgery" sense of humour and be a good doctor, most not only agreed but declared it essential. As one put it; "All humour is laughing at misfortune, and if you're surrounded by it every day you're bound to laugh at it more than, say, someone who works in Thorntons." "Surely if you work in a chocolate shop you see lots of unfortunate fat people?" "Yes, but they're not going to buy your chocolates if you laugh at them, so you don't do it. At least not in front of them."

And there's the rub. The students decided it was both ethical and practical to have prejudicial or disrespectful attitudes in the privacy of your own mess or coffee room in a "you've got to laugh or you'll go under" sort of way, provided they don't spill out in a consultation. This, it appears, is where surgeons fall down. "Some of them say exactly the same things in public as they do in private." "Isn't that just refreshing honesty?" "Not when it causes so much distress. It's as if they're so powerful and unaccountable that theirs are the only feelings that matter." Although in theory every patient has a right to a second opinion if a doctor upsets you, the practical reality is that it's very difficult. Much more difficult than say, switching chocolate sellers - unless you're prepared to pay. I'm no great fan of private medicine, but it's amazing what the promise of lucre does to a bedside manner. No one mentions salami surgery in the Balmoral Clinic.

All this surgeon bashing is enough to make us GPs feel smug, but we're not in the clear by any means, especially when it comes to obesity. After smoking, this is the biggest single cause of premature death in the UK, and much more besides. Overweight patients have lower self-esteem and more psychological problems than any other single patient group, including cancer sufferers. Many of them never go near a chocolate shop, and many eat no more than slim patients. Yet virtually every obese patient I've met has had a doctor say to them at some stage "there were no fat people at Belsen". This a typical arsey doctor's way of saying "If you ate less, you'd lose weight" - which is undoubtedly true - but the message is lost in the gag and patients leave feeling more stigmatised than ever. Alas, they rarely tell the doctor how upset they are. It took the Daily Mail to blow the whistle when a doctor told a woman that "nobody fat walked out of Auschwitz", without realising she was Jewish.

I recently met a woman who had conquered her obesity but said at the time how it took over her life. "Every decision I made was coloured by my low self-esteem. I was buying a pair of shoes and the sales assistant asked me if I wanted some polish for them. She chose a shade I was certain was wrong, but I didn't say anything because I'm sure she'd have thought "Silly fat cow, what does she know" - so I let her sell me the wrong one." If over-weight patients can feel so threatened by shoe fitters, imagine what doctors do to them