The evolution of obesity diagnosis and care

Paul Mulholland speaks to obesity specialist Dr Michael Crotty about recent statements from the International Obesity Collaborative that define the changing concepts within the field

World Obesity Day took place earlier this month on 4 March. In the lead up to the day, the International Obesity Collaborative (IOC) made two significant consensus statements. The first of these related to body mass index (BMI). The second concerned weight loss versus obesity management.

The first statement highlights that BMI, as a measure used to screen for obesity, neither defines the disease nor replaces clinical judgment.

“Social determinants, race, ethnicity, and age can modify the risk associated with a given BMI,” according to the statement.

“Successful obesity management should be measured by the health and quality-of-life goals established through shared decision-making by the patient and their healthcare provider rather than changes in BMI alone.”

The second statement points out that obesity care and weight loss are not the same.

“Obesity care delivered by qualified clinicians consists of evidence-based options that address comorbidities of obesity (diabetes, hypertension, hyperlipidemia, etc) and improve wellbeing,” according to this statement. “Obesity care is about health, not weight. Weight loss is just one outcome of obesity care.”

The IOC is a global initiative aimed at addressing the disease of obesity on an international scale.

Both statements are indicative of the changing concepts behind obesity care, according to Dr Michael Crotty, a GP based in Dalkey, Co Dublin, who specialises in obesity.

Dr Crotty is a member of the clinical advisory group of the National Clinical Programme for Obesity and co-Chair of the adult weight management subgroup. Dr Crotty was awarded SCOPE certification in 2018 and selected as a participant for the SCOPE Leadership Programme with the World Obesity Federation. The certification is open to healthcare professionals with at least six months’ practical experience related to obesity management. He was also recently recognised as a SCOPE national Fellow.

BMI

Dr Crotty said the statements reflect the need for greater understanding about obesity and its effect on health.

“Body mass index is what we have previously used to diagnose obesity,” he told the Medical Independent (MI) in relation to the first statement.

“If you had a BMI greater than 30, we would consider a diagnosis of obesity. We’re probably shifting away from that now. We’re looking more at the effect that excess weight has. So, if somebody is living with excess weight and it’s impacting on their health, then we would make a diagnosis of obesity.”

Dr Crotty said the limitation of BMI is that, on an individual basis, it does not provide meaningful insight into a person’s health. “Because it’s a measure of size versus height, it doesn’t tell us the distribution of weight, or body composition; it doesn’t tell us if somebody is experiencing metabolic issues.”

However, he added that the benefit of BMI is that it is “easy and it is measurable”.

“It is very reproducible,” Dr Crotty said.

“And it’s acceptable to most people to measure it, as long as we do it in the right context. So, it can be helpful to screen people. But then we need to look further at the person to see is their health affected by excess weight. And that’s when we would start talking about obesity as a medical issue, as a chronic disease. It’s a shift in the way we think about obesity where it is not just about size or the number on the scales.”

Obesity care vs weight loss

Dr Crotty said the second statement, on the difference between obesity care and weight loss, is also informed by the primacy of health.

“Weight loss would be something that is generally influenced by socio-cultural norms: There is a focus on the struggle and journey; it is often done with a goal in mind, in order to be a certain size or fit into certain clothes, with an end point. It also involves restriction and inflexible patterns of eating.”

He stressed how this was not the same as obesity care.

“And we are providing obesity care. We are treating somebody. We are either treating them with life interventions, nutrition therapies, or behavioural strategies. We are supporting them. We might be treating them with pharmacotherapy. It is lifelong treatment because this is a chronic disease. It is not something that we cure.”

In terms of obesity care, the focus is more on health than weight.

“Somebody who wants to lose weight may have a cultural desire to be thin, but they don’t necessarily have a medical condition.”

These new concepts have been informed by an increasing range of treatment options for obesity, Dr Crotty said.

“There is also more of a realisation that this is a very sensitive area of healthcare; it’s very nuanced,” he told MI.

In addition, the statements have been influenced by the need to challenge “the stigma of bias and the lack of understanding of obesity as a chronic disease”.

“In society, there is this striving for people to be thin for aesthetic reasons, for cultural reasons,” he said.

Dr Crotty argued “we need to be moving away from diet culture; that everybody should be the same size and there is one way of being”.

He also said a focus on weight loss, rather than health, can lead to unhealthy, unsustainable patterns of behaviour.

Consensus

However, Dr Crotty admitted progress in the area has been hampered by the difficulty in getting consensus on the nature of obesity among stakeholders.

“There are different players in this; it’s not just healthcare professionals and different specialties. There are other parts of society, such as the diet industry, that prioritise and push for weight loss.”

Dr Crotty also said, within healthcare, not everyone easily accepts that obesity is a chronic disease.

“They still have this old-fashioned thought that it is an issue of lifestyle, motivation, and willpower, despite all the scientific evidence telling us that is not the case. The evidence tells us obesity is genetically linked, it is neurologically regulated, and is certainly heavily environmentally influenced too.”

He stated that patients with obesity need to be supported in the same manner as patients with other chronic diseases.

General practice

But Dr Crotty said there is increasing recognition of obesity as a chronic disease within general practice. He said one reason for this is greater education on the issue and noted the work the ICGP has done to raise awareness.

“Patients are also advocating for themselves, wanting to discuss different options, and that provides opportunities to start conversations,” Dr Crotty explained.

“But there are also challenges in that the information people have received from non-healthcare professionals may not be aligned with our understanding of things.”

While he said the education on obesity is improving, “there is still significant work to do.”

“The challenge in general practice is that we have an ever increasing amount of work. And, certainly, when it comes to obesity, [GPs] are not adequately supported or resourced to treat it in primary care at the moment.”

He pointed out that obesity is not part of the structured chronic disease management (CDM) programme in general practice.

“In my view it should be included because it is not a quick fix. This is a long-term medical issue that has a major impact on some people’s health. It should be treated like we treat other chronic diseases. It is not more or less important.”

Dr Crotty said that, currently, the CDM programme is targeting some of the complications of obesity, such as hypertension and diabetes, rather than one of the main underlying causes.

Future

If it is adequately resourced and supported, the HSE’s model of care for obesity provides a strong framework for healthcare in the area, both now and into the future, according to Dr Crotty.

“With the model of care and the [National] Clinical Programme for Obesity, hopefully, there will be greater access to specialist care. And none of this detracts from prevention, and public health measures, which are also hugely important.”