Boris Johnson's War on Fat

The metabolically unhealthy have suffered disproportionately from coronarvirus. The PM wants to tackle the nation's weight problem but how can he succeed where decades of public health advice have failed?

As a doctor and seasoned weightwatcher, I welcome the news that the Prime Minister is to declare war on fat. I do however hope that Boris is taking the right advice. If his battle of the bulge is to succeed, he must ignore Public Health England, authors of the miserable Eat Well Guide which encourages us to eat low-fat meals based on starchy carbohydrates, and listen instead to experts with a proven track record in helping people to lose weight and keep it off.

Dr David Unwin, a GP in Southport, has enjoyed runaway success helping patients to lose weight and improve their health. It began after an encounter with a patient who’d achieved stunning weight loss and reversed type 2 diabetes. All doctors do well to remember the advice of the great Sir William Osler, godfather of diagnostic medicine: “Listen to your patient, they are telling you the diagnosis”. And in this case, the patient went one better: Dr Unwin listened, and she told him the cure. She’d ditched the official “eat less, move more” advice and followed a low-carbohydrate diet.

Intrigued, he started a pilot study in his practice to see if other patients could experience the same benefits by cutting out sugar and starchy carbohydrates. He has since helped over a hundred patients to lose weight - an average 8.5kg each – and improve their blood sugar levels. Forty per cent of his type 2 diabetic patients who took this approach have been able to stop their anti-diabetic medications. In 2017/18, the practice’s alternative dietary and lifestyle advice proved so successful that it saved £57,000 on medications for type 2 diabetes and high blood pressure. This is surely the sort of saving that, if realised on a larger scale, ought to delight a government heading into the post-coronavirus era.

Boris could also seek the advice of Mr Andrew Jenkinson, an NHS weight-loss surgeon whose recently published book Why we eat (Too much) details his years of experience with obese patients and his research on how we get fat and what we can do about it. Surprisingly for a surgeon, his preferred solution does not involve surgery. Instead, he explains how the quality of our food affects our hormones and determines whether we put on or lose weight. He advises his patients to shun the processed food that pervades modern life (and, implausibly, is both included in Public Health England’s guidance and practically the only food available in NHS hospitals) – and to eat food that your great-grandmother would recognise.

The key consideration common to the approaches of Dr Unwin and Mr Jenkinson - notably lacking from the official UK guidance - is satiety. Any regime that requires its adherents to go hungry is doomed to fail eventually and can even make things worse. The NHS’s 12-week weight loss plan is based on the “eat less, move more” paradigm, focusing on calories in-calories out. But as Mr Jenkinson explains so well in his book, human physiology is a lot more complicated than that. Yes, you can cut calories dramatically and lose weight but you are likely to regain it in the long run. Proponents of the calories in-calories out approach often invoke the first law of thermodynamics – that energy cannot be created or destroyed in a closed system – to argue that only calories matter and the overweight are simply eating too much. But the human body is not a closed one compartment system – processes that result in fat loss or gain are complex and the body does not treat all calories equally. This is demonstrated neatly in a study led by Kevin Hall, a senior investigator from the US National Institutes of Health in which he followed up contestants from The Biggest Loser, a US reality TV programme where the obese compete to lose the most weight through a gruelling diet and exercise regime. Hall followed the contestants up for 6 years after the season finale, by which time almost all of the weight they had lost was regained. But even worse, their resting metabolic rate – the energy burnt every day just from sitting around – had decreased by an average of over 600 calories a day. Their bodies seemed to have adapted to the reduction in intake and could now make do with less, suggesting that weight loss would be even harder to achieve in the future.

Public Health England state that their dietary guidance is evidence-based, and yet they ignore the issues that matter most: does this approach work in the real world and can patients maintain their successes over the long term? The UK’s ever-increasing rates of obesity and related conditions such as type 2 diabetes and high blood pressure should give us all pause to think. Of course, Public Health England might argue that their advice is sound – it’s the public who are failing by not following it. I believe, however, that the public have tried their best to engage with official advice, and have been rewarded with a never-ending cycle of hunger and self-reproach. I therefore favour an alternative explanation for our burgeoning obesity rate: the advice is wrong.

There are plenty of other clinicians and researchers, in addition to the three mentioned above, who are getting results and who would make valuable contributions to any national effort to fight the flab. This is a war I think Boris can win, but he must pick his generals wisely.