This is the first in a series of articles about how ideological interest groups react when their institutional preferences are challenged by practical solutions.

 

The Department of Health and Social Care says that obesity costs the NHS ‘up to £6.5 billion a year’. The health secretary Wes Streeting has claimed that it costs the NHS £11 billion a year. When wider societal costs, including lost productivity, are included, Frontier Economics estimated that obesity cost Britain £58 billion in 2020, and when they made a further estimate to include the cost of people being overweight in 2023, this rose to £98 billion, of which £19.2 billion were direct costs to the NHS.

Obesity is routinely referred to as a ‘crisis’ in the UK and elsewhere. Fifteen million adults (28 per cent) have a body mass index of 30 or more and are therefore classified as obese. The number of obese Britons has been gradually growing for decades and none of the anti-obesity policies enacted so far, such as the sugar tax and traffic light labelling on food, has made any tangible difference. Some countries have gone further. Hungary, for example, has an extensive system of taxes on food that is high in fat, salt or sugar (HFSS). Chile has had mandatory health warnings on HFSS food since 2016 and has banned the use of cartoon mascots such as Tony the Tiger. Both countries have seen obesity rates continue to rise.

Given how seriously public health campaigners take obesity as a health problem, you might think that they would be delighted to find something that makes people lose a great deal of weight in a short space of time. But you would be wrong. A new generation of pharmaceuticals that have been shown in randomised controlled trials to help people lose an average of 15 per cent to 20 per cent of their body weight have been given a cautious welcome at best by those who should be most excited by them.

The drugs have attacked from the right, with some commentators suggesting that using drugs to overcome obesity is a form of cheating which absolves people from using willpower, but they have mostly been attacked from the left where the  institutional preference is for radically changing the ‘food environment’ through taxation, advertising bans and mandatory food reformulation.

In 2023, a Guardian headline exclaimed that the arrival of effective weight-loss drugs was ‘no excuse to let junk food companies off the hook’. The Guardian’s health editor Sarah Boseley called on the government to reject the ‘quick fix’ of semaglutide (AKA Wegovy/Ozempic) and instead ‘promote healthy diets, redesign our towns to get people walking and help shift societal values towards food’, neglecting the fact that governments have been promoting healthy diets for decades and that our towns have already been designed (I can’t comment on ‘societal values towards food’ as I don’t know what it means). Another Guardian writer has complained that weight-loss drugs are ‘trying to solve the wrong problem’ and that the real issue is ‘primacy of work, long hours, low pay, hustle culture, structural inequalities, poverty and precarity.’

Even those who not hostile to the drugs per se are concerned that having a proven remedy for obesity will be a distraction from the real task of fundamentally changing society with untested policies and giving more power to the state. Giles Yeo, a geneticist who has written several books about obesity, last year told the Guardian that ‘I do fear, and this is a true fear, that actually not only our government, but many governments and policymakers, may very well use [these drugs] as a cop-out not to make the hard policy decisions.’ In case you’re wondering what a hard policy decision looks like, he has since explained to the BBC that ‘we’re going to have to lose some liberties’.

Dr Margaret McCartney, a writer and GP, says that her ‘big concern’ about the drugs is that ‘the eye is taken off the ball with stopping people getting overweight in the first place’ which, for her, means changing ‘the obesogenic environment’. The restaurateur-turned-campaigner Henry Dimbleby is worried that ‘we will increasingly drug our way out of the problem’ and that this will ‘move the profits from the food companies to the drug companies.’ Nesta, a state-funded body that describes itself as an ‘innovation agency for social good’, is a prominent defender of the public health orthodoxy and is a fierce proponent of state-sanctioned food reformulation. When, in January 2023, it produced a report looking at ‘what would be required to halve obesity’, weight loss drugs were not even mentioned. Instead it focused on ‘population-level interventions in the food environment such as reformulating food, reducing junk food advertising and shifting price promotions towards healthier foods’. Pressed on the issue of weight-loss drugs, Nesta wrote a blog post in which they said they were worried that their use ‘might well deepen the emphasis in the public discourse on a “personal responsibility narrative”’.

In October 2024, the House of Lords Food, Diet and Obesity Committee published a 181 page report which contains just one passing reference to weight loss drugs. The committee acknowledged that ‘there is increasing interest in the potential of new medicines such as semaglutide’ but effectively dismissed them on the basis that they are ‘a targeted rather than a population measure’. They also noted that the drugs are ‘expensive’ and that halving the rate of obesity by prescribing them ‘would place considerable additional pressure on the NHS’.

The reference to cost is telling. Isn’t obesity supposed to be such a burden on public services that almost any effective counter-measure would reduce the ‘pressure on the NHS’? A legitimate criticism of the new generation of weight-loss drugs is that they are expensive and will continue to be expensive until they go off-patent in the 2030s. A four week supply of Wegovy (semaglutide) or Mounjaro (tirzepatide) typically costs around £170. If we assume, perhaps optimistically, that the NHS could negotiate a better price of £130, it would cost £26 billion per annum to give them to every obese adult in the UK. If every overweight person were also given it, it would cost a total of £58 billion. In the context of the £98 billion that obesity is said to cost Britain, this sounds potentially cost-effective, but a closer look at the figures suggests that it would actually require a massive net increase in government spending. Of the £98 billion in Frontier Economics’ latest estimate, £56.6 billion is comprised of the intangible costs of lost years of life to obese or overweight individuals, and £15.1 billion is made up of lost productivity costs which mostly, if not entirely, are borne by obese employees through lower wages and unemployment.^[1] A further £6.5 billion comes from informal social care costs, such as a husband looking after his wife, based on an estimate of how much it would cost to employ someone to do this work if they were being paid.

None of these ‘costs’ are borne by the government. The only direct cost to the taxpayer is the £19.7 billion attributed to NHS treatment and formal social care, but this is a substantial overestimate as it does not include savings to the public purse from obese individuals dying prematurely, nor does it account for the counterfactual in which the individuals concerned were not obese and lived long enough to require other healthcare needs. An analysis published by the IEA in 2017 looked at the net cost of overweight and obesity to the government in England and Wales, including savings to the state, and found that the total was less than £2.5 billion per annum and could be zero.

The government therefore finds itself on the horns of a dilemma. Either it can accept the inflated estimates of how much obesity supposedly costs Britain, in which case spending £26 billion per year on weight-loss drugs makes sound financial sense, or it can accept that the real cost of obesity is a fraction of what has been claimed. Public health campaigners have an incentive to exaggerate the negative externalities associated with obesity, but so too does the pharmaceutical industry. It is perhaps no coincidence that the report from Frontier Economics which claimed that obesity  was costing £58 billion a year was commissioned by the manufacturers of Wegovy, Novo Nordisk.

Whether or not these drugs are cost-effective depends on which costs you consider relevant, but they are at least effective – and that sets them apart from the ‘population level’ policies that organisations such as Nesta continue to cling to. While we have RCTs showing that Wegovy and Mounjaro work, we also have RCTs showing that food reformulation doesn’t work. The USA recently reported an unprecedented two per cent decline in the obesity rate which, as John Burn-Murdoch argued in the Financial Times, can only plausibly be attributed to weight loss drugs, which one in eight Americans have now used.

No policy promoted by public health campaigners has reduced obesity anywhere in the world by even one per cent. No wonder they’re jealous.

 

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^[1] Although lost productivity makes up a large share of all cost-of-obesity estimates, campaigners have objected to productivity being taken into account when obesity treatments are available. When Wes Streeting announced plans to give Mounjaro to obese jobseekers, the idea was described as ‘unethical’ by the public health academic Simon Capewell because it prioritised those who could be economically active. Another public health academic, Dolly van Tulleken, agreed, saying that it was questionable whether the government should be ‘measuring people based on their potential economic value’.