The author Johann Hari believes the new generation of weight-loss drugs, which includes Ozempic, Wegovy and Mounjaro, will prove as era-defining as Prozac or the contraceptive pill. He’s probably right, and yet it takes a certain boldness to write a book assessing their impact now, while the drugs are still so new. Ozempic, a brand name of the medication semaglutide, was first approved as a diabetes treatment in 2017 and hit Hollywood as the ultimate diet drug around five years later. Wegovy – semaglutide at a slightly different dosage, prescribed specifically for weight loss – has been available on the NHS since September 2023. It’s still possible that we’ll uncover some new and dangerous side-effects, and that semaglutide joins the likes of fen-phen – which was touted as a miracle anti-obesity drug before being discontinued in the 1990s as it caused heart problems. But Novo Nordisk, which makes both Ozempic and Wegovy, recently became the most valuable company in Europe. Graham MacGregor, a professor of cardiovascular medicine at Queen Mary University of London, predicts that in a decade 20-30 per cent of the population will be on these weight-loss drugs.
Hari is good at turning out eminently readable popular science books on of-the-moment subjects – fracturing attention spans, depression, the war on drugs – and his latest book, Magic Pill: The Extraordinary Benefits and Disturbing Risks of the New Weight Loss Drugs, is no exception. He knows how to deploy a good anecdote and personalise big, political issues, and in Magic Pill he intersperses interviews with experts and scientists with an account of his own struggles with his weight and addiction to junk food: he once received a Christmas card from a fried-chicken shop that was addressed “To our best customer”. It wasn’t even the fried-chicken shop he went to most often.
Hari takes Ozempic and succeeds in losing weight, but he retains a certain ambivalence towards it and an uncertainty over his own motivations: is he doing this for his health or for vanity, and how much does that distinction matter? His own story helps him explore the complexities and wider politics of Ozempic in a nuanced, non-judgemental way. He understands, instinctively, that food culture and body weight are inherently emotional issues, and that we cannot understand rising rates of obesity, or the rise of Ozempic, with reference to health and science alone.
Much of the ground that Hari covers will be relatively familiar if you’re interested in Ozempic and have been reading some of the excellent long-form journalism written about it, mostly in the US. He explores whether the rise of anti-obesity drugs will make governments less likely to take action that tackles the root causes of obesity and diet-related illness, such as our modern reliance on hyperpalatable ultra-processed food, and argues, quite sensibly, that the people who will benefit from Ozempic most cannot afford to wait for our entire food culture to be fixed. He points out the danger that weight-loss drugs will be abused by people with eating disorders and may also trigger a new wave of such disorders by reinforcing a cultural ideal of extreme thinness: for all the talk of body positivity and self-care, the celebrities who help set our beauty standards have never been so painfully thin. Hari also explores the stigma against fatness, and why some in the fat-acceptance movement oppose the drugs. But he remains convinced of the health benefits of taking Ozempic because of the evidence that it reduces the risk of heart attacks and strokes in people with type 2 diabetes.
Within days of its publication Magic Pill kicked up a social media storm, and Hari had to apologise for incorrectly claiming that the restaurant critic Jay Rayner once said that “Ozempic robbed him of his pleasure in food so severely that even in great restaurants in Paris, he couldn’t find any joy.” Rayner described this on Twitter/X as “complete and utter bollocks” and directed readers to the only column he has written on Ozempic, in which he explains why he would never take it. To make matters worse, Hari responded by explaining that he had confused an article by Rayner with an article by “Layla Latif” in the same paper. Only Leila Latif, who did indeed write about losing pleasure in food, wasn’t taking Ozempic. Hari said he was “gutted” that he and his fact-checkers missed the error. (He credits three fact-checkers in his acknowledgements.) Such sloppiness would be embarrassing for any writer, but it’s a particular problem for Hari, who lost his job at the Independent in 2011 due to prolific plagiarism. Once broken, readers’ trust is very hard to regain: every time Hari was able to enliven his writing with the perfect illustrative anecdote, a small, unkind part of my brain would think: “How do I know this really happened?”
Which is a shame because Hari has important insights. The strongest and most interesting parts of the book explore how anti-obesity drugs might affect the brain and our psychology. Our knowledge of the neurobiological impact of Ozempic is tentative at best: some scientists believe the drugs dampen how the brain responds to reward, suggesting that it not only reduces a person’s appetite for food but also makes alcohol and drugs less appealing. Experiments on rats have suggested that being injected with GLP-1 agonists (the class of drugs, such as Ozempic, that mimic the hormone GLP-1, which is linked to appetite) makes them drink less alcohol and causes them to consume less cocaine and heroin (some lab rats really are forced to live hard).
There is anecdotal evidence of the same effect in humans: it seems that some people who take Ozempic find they have a reduced desire to indulge in other addictive behaviour, from drinking alcohol to compulsive shopping – but the clinical trials are ongoing, and the early results are mixed. Meanwhile, other scientists argue that Ozempic doesn’t affect the brain’s reward system but instead bolsters the aversion system, so that people feel sated more quickly.
While the underlying mechanisms remain unclear, what is plain is that even small changes to these systems could have significant effects on a person’s life. Dampening someone’s reward response could produce a form of anhedonia, a reduced ability to experience pleasure. Hari himself wondered if Ozempic had slightly blunted his emotional responses so that he felt not exactly depressed, but a little less joyful. This is the kind of thing that could interfere with our relationships in profound ways. One researcher imagines the case of a woman who starts taking Ozempic to lose her baby weight: might the drugs alter how she bonds with her baby? And if women take Ozempic while pregnant, how might it affect their baby’s long-term neurodevelopment?
More directly, we know that losing one’s appetite – and losing weight – can significantly affect a person’s mood and psychological well-being. As Hari observes, if for some people overeating serves a psychological function – perhaps it is a way to self-soothe, a distraction from pain – then what happens when this coping mechanism is taken away? He notes that roughly one in ten people who have bariatric surgery (procedures that change how food is processed in the digestive system to drive weight loss) develop a new addiction, sometimes to alcohol or gambling or drugs or shopping, afterwards. This is called “addiction transfer”, when the new compulsive behaviour fills the psychological void left by the former addiction. It is estimated that around 17 per cent of people who have bariatric surgery develop psychiatric problems severe enough to require inpatient treatment, and the surgery seems to increase a person’s risk of suicide, perhaps because people are not given support for the emotional problems that underlay their relationship with food.
Reading Magic Pill, I thought of how essential it is that the public conversation about food culture and obesity begins engaging with the emotional and psychological dimensions of the problem. Policymakers can talk endlessly about weight and waistlines and school dinners and sugar taxes and restaurant calorie counts, but they pay too little attention to how food, which ought to be a source of pleasure and nourishment and togetherness, has become the source of so much guilt and shame. They need to find ways to consider the psychological consequences of growing up in a obesogenic food culture that vilifies fatness. These are things that no diet drug can fix. The best-case scenario, in Hari’s view, is that the likes of Ozempic do work well long term, and this success prompts a long-overdue reckoning with our dysfunctional food system. For now, such an outcome feels unlikely.
Magic Pill: The Extraordinary Benefits and Disturbing Risks of the New Weight Loss Drugs
Johann Hari
Bloomsbury, 336pp, £20
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[See also: How hormones rule our lives]
