Discussions with patients about sensitive subjects are part of clinical practice, from talking about end-of-life planning to sexual health. But it seems that excess weight is one conversation where a lot of doctors are reluctant to make the first move.

Obesity is a major public health issue, and yet few doctors feel confident about raising the subject of weight during consultations. "When I talk to GP audiences, the response is pretty consistent," says Dr Rachel Pryke, a GP with a long-standing special interest in weight and nutrition, who has championed the issue within the RCGP and runs training workshops for primary care staff.

"If I ask, 'Who has had difficult conversations when trying to discuss weight?' nearly everyone puts their hand up. When I ask if anyone has had a complaint, nearly half put their hand up. And in response to the question, 'How many avoid talking about it?' nearly all their hands go up again."

Part of the problem is practical - a ten-minute consultation leaves little time to talk about anything other than the presenting problem - but Rachel's experience suggests that many doctors also have difficulty in finding the right words or misjudge their communication. "I'll put my hand up too and agree it's hard, because I've had complaints myself over the years when I have got it wrong.

"Often the problem is that the patient feels that a casual judgement is passed during a consultation before they have had a chance to offer their perspective, or that parental inadequacies are being implied when the patient is a child."

While a patient may not make a complaint, a poor choice of words or flippant comment can cut them to the quick, says Rachel. "I've seen many reports of patients shying away from seeking support because they have previously experienced what they perceive as a judgemental attitude from a doctor in the past. It's even been suggested to them that they don't realise they have a weight problem, or they are lying about trying to lose weight. There can often be quite a significant bridge that needs to be rebuilt."

However, simply avoiding the issue is not an option either, given doctors' duty of care to patients who could be at greater risk of adverse health, as well as the scale of the public health crisis that threatens to engulf the health service.

The statistics are frightening. Obesity affects more than a quarter of adults in England (25.9%), a similar proportion in Wales and 31% in Scotland, while many more are categorised as overweight - which, if not addressed, could develop into obesity. What's more, excess weight gain can start at an early age; according to data collected by the National Child Measurement Programme, 10.1% of reception age children (aged four to five) and 23.4% of children in year six (ages 10-11) were classified as obese in 2021/22.

The causes are incredibly complex and entwined, Rachel observes. "There have been changes across so many different aspects of our lives over the last 30-40 years, from activity levels to diet. Ultra-processed foods that are very high in fat, sugar and salt dominate the market and these are being pushed through aggressive advertising by the food industry, which is having a huge impact on society.

"We've also known for years that weight and eating behaviour has a genetic influence, but our susceptibility to the obesogenic environment is widely misunderstood. You might argue that our genes haven't changed, but another way to look at it is that some of the population were always at risk, and we're now living in this toxic environment where these people are more susceptible - and there are strong links to deprivation with that too. I think the food industry has a big responsibility for the problem we are facing, but sadly many politicians would rather carry on blaming the individual."

Public attitudes to weight and obesity need to change, she believes. "There are some hugely outdated and prejudiced views out there surrounding personal responsibility and willpower and it's such hard work to change perceptions. We're still on that journey of embedding people's understanding of obesity as a disease process, and I include myself in that because I was initially reluctant about pathologizing such a large proportion of the population. However, the more I understood it, the more I saw the value because it challenges people's prejudices. We don't particularly blame someone for becoming diabetic or having a heart attack, but we haven't reached that point with obesity."

Nonetheless, Rachel believes there has been real progress in raising GPs' awareness and understanding since she first took up the issue back in 2005 after writing a book on childhood obesity. At that point the RCGP had no guidance and no personnel looking at obesity, and invited Rachel to work with them to set up a programme on nutrition and weight which led to the establishment of the GPs with an Interest in Nutrition Group (GPING).

"The starting point has to be the medical profession and there has been a lot of good work here," she says. "I've certainly noticed that among younger doctors there's much more acceptance that there are biological factors that impact on obesity pathways. We've moved a long way to embedding our approach in science, rather than social blame."

Although GPs can do little to change the socio-economic drivers of obesity, Rachel believes they can make a huge difference to the lives of patients by having a meaningful conversation, and has some useful tips on how to broach the subject.

"Just skirting around topic is probably a recipe for saying the wrong thing. But there are straightforward openers and two come immediately to mind. The first is to ask for permission: 'Would it be ok if we talk about your weight?' or 'Would it be ok if we talk about your child's growth?' The second is just talking about feelings: 'How do you feel about your weight, your family's eating habits, exercise, fitness etc?'

"The advantage with this approach is it naturally leads you to finding out that patient's story. They might respond that they feel fantastic, they have started going to the gym and they have just lost three-quarters of a stone - or they could say, 'I'm so glad you asked, because I've been worried sick about my weight and don't know what to do.'"

"Rather than conveying our views without having the faintest idea what's been going on, asking about feelings allows the patient to say, 'This is where I am and this is where I'd like the conversation to go'. That can lead to valuable conversations where you can see the intensity of self-blame and failure that someone who has struggled with their weight can experience. Patients can open up about a lot of non-weight related stuff, including deprivation or abuse, that made food important in their lives. It can be life-changing because there is a sense of a problem - finally - shared."

The key for Rachel is that GPs are guided by the patient's agenda during every consultation. "I'd be horrified if there was some sort of national strategy to introduce weight and lifestyle advice into every consultation. Framing it in terms of feelings enables us to talk about lifestyle and weight, but the patient gets to direct how that conversation goes."

Language is significant too, Rachel notes.  "It's not really the words per se, it's the context. Terms like chubby might sound friendly in a story, but it could be very offensive in a medical setting for someone who is sensitive about their weight. In general, I think that professionals should be using the appropriate factual terminology, although I probably wouldn't use the word obesity to a child or in their hearing."

Patients' language can also be instructive, she adds. "They might use euphemistic terms like describing themselves as big-boned or seek to shrug off concerns. But rather than assuming they are in denial or don't know they have a problem, it's likely to indicate this is a situation they can't resolve by themselves and need help."

This isn't surprising when you consider how common it is for people to regain the weight they lost through dieting, and Rachel warns against 'ploughing in' with superficial advice. "Unfortunately, there are some health advocates who say if only you do this then everything will be marvellous, but obesity is highly resistant to lifestyle modification.

"For someone who has a BMI of say 25.5-26, lifestyle advice is absolutely the right thing because the chances are they have had very gradual weight gain over the last ten years and that trajectory will continue until they reach a tipping point. Small changes for these patients can make a difference, but we need to target those interventions appropriately and it's a tall order to get that right.

"Where someone has obesity, it's not enough to tell them about the gym down the road and give them some vouchers, especially if they have a history of yo-yo dieting. In my view we've got to look we've got to look more at the medical options for patients with resistant established obesity, because it is a biological disease process."

This might include the use of semaglutide drugs. NICE has recently recommended Wegovy as an option for weight management, alongside a reduced-calorie diet and increased physical activity, but only in certain conditions, and the launch of the drug in the UK was delayed amid concerns about supply. However, tackling the obesogenic environment remains the priority and Rachel wants the government to take this issue seriously and stop engaging in a "completely outdated blame game".

From a medical perspective, Rachel wants GPs to have confidence that weight is part of their remit, and to be able to raise it during relevant conversations so patients feel listened to and supported. She points to resources on the RCGP website and the British Society of Lifestyle Medicine, as well as local networks for interested GPs.

She believes the tide is turning. "When I started, I couldn't get people to come to training on obesity and I had to include it with other stuff," she remembers. "Now we can easily fill a whole conference on obesity because there is mainstream acceptance of it as a health issue and a risk factor in so many other diseases."

Interview by Susan Field.