Has a diet of ultra-processed food sentenced us to an addictive relationship with salt, fat, and sugar?

Ever since I was a teenager, I have dreamed of shedding a lot of weight. So when I shrank from 203 pounds to 161 in a year, I was baffled by my feelings. I was taking Ozempic, and I was haunted by the sense that I was cheating and doing something figures immoral. I'm not the only one. In the US (where I now split my time), over 70 percent of people are overweight or obese, and according to one poll, 47 percent of respondents said they were willing to pay to take the new weight-loss drugs. It's not hard to see why. They cause users to lose an average of ten to 20 percent of their body weight, and clinical trials suggest that the next generation of drugs (probably available soon) leads to a 24 percent loss, on average. Yet as more and more people take drugs like Ozempic, Wegovy, and Mounjaro, we get more confused as a culture, bombarding anyone in the public eye who takes them with brutal shaming.

This is happening because we are trapped in a set of old stories about what obesity is and the morally acceptable ways to overcome it. But the fact that so many of us are turning to the new weight-loss drugs can be an opportunity to find a way out of that trap of shame and stigma and to a more truthful story.

In my lifetime, obesity has exploded, from being rare to almost being the norm. I was born in 1979, and by the time I was 21, obesity rates in the US had more than doubled. They have skyrocketed since. The obvious question is, why? And how do these new weight-loss drugs work? The answer to both lies in one word: satiety. It's a concept that we don't use much in everyday life but that we've all experienced at some point. It describes the sensation of having had enough and not wanting any more.

The primary reason we have gained weight at a pace unprecedented in human history is that our diets have radically changed in ways that have deeply undermined our ability to feel sated. My father grew up in a village in the Swiss mountains, where he ate fresh, whole foods that had been cooked from scratch and prepared on the day they were eaten. But in the 30 years between his childhood and mine, in the suburbs of London, the nature of food transformed across the Western world. He was horrified to see that almost everything I ate was reheated and heavily processed. The evidence is clear that the kind of food my father grew up eating quickly makes you feel full. But the kind of food I grew up eating, much of which is made in factories, often with artificial chemicals, left me feeling empty and as if I had a hole in my stomach. In a recent study of what American children eat, ultra-processed food was found to make up 67 percent of their daily diet. This kind of food makes you want to eat more and more. Satiety comes late, if at all.

One scientific experiment, which I have nicknamed Cheesecake Park, seemed to me to crystallize this effect. Paul Kenny, a neuroscientist at Mount Sinai Hospital in New York, grew up in Ireland. After he moved in 2000 to the US, when he was in his 20s, he gained 30 pounds in two years. He began to wonder if the American diet has some kind of strange effect on our brains and our cravings, so he designed an experiment to test it. He and his colleague Paul Johnson raised a group of rats in a cage and gave them an abundant supply of healthy, balanced rat chow made out of the kind of food rats had been eating for a very long time. The rats would eat it when they were hungry, and then they seemed to feel sated and stopped. They did not become fat.

But then Dr. Kenny and his colleague exposed the rats to an American diet: fried bacon, Snickers bars, cheesecake, and other treats. They went crazy for it. The rats would hurl themselves into the cheesecake, gorge themselves, and emerge with their faces and whiskers totally slicked with it. They quickly lost almost all interest in the healthy food, and the restraint they used to show around healthy food disappeared. Within six weeks, their obesity rates soared.

After this change, Dr. Kenny and his colleague tweaked the experiment again. They took all the processed food away and gave the rats their old healthy diet. Dr. Kenny was confident that they would eat more of it, proving that processed food had expanded their appetites. But something stranger happened. It was as though the rats no longer recognized healthy food as food at all, and they barely ate it. Only when they were starving did they reluctantly start to consume it again.

Though Dr. Kenny's study was in rats, we can see forms of this behavior everywhere. We are all living in Cheesecake Park, and the satiety-stealing effect of industrially assembled food is evidently what has created the need for these medications. Drugs like Ozempic work precisely by making us feel full. Carel le Roux, a scientist whose research was important to the development of these drugs, says they boost what he and others once called "satiety hormones."

Once you understand this context, it becomes clear that processed and ultra-processed food creates a raging hole of hunger, and these treatments can repair that hole. Michael Lowe, a professor of psychology who has studied hunger for 40 years, told me the drugs are "an artificial solution to an artificial problem."

Yet we have reacted to this crisis largely caused by the food industry as if it were caused only by individual moral dereliction. I felt like a failure for being fat and was furious with myself for it. Why do we turn our anger inward and not outward at the main cause of the crisis? And by extension, why do we seek to shame people taking Ozempic but not those who, say, take drugs to lower their blood pressure?

The answer, I think, lies in two very old notions. The first is the belief that obesity is a sin. When Pope Gregory I laid out the seven deadly sins in the sixth century, one of them was gluttony, usually illustrated with grotesque images of overweight people. Sin requires punishment before you can get to redemption. Think about the TV competition show The Biggest Loser, on which obese people starve and perform extreme forms of exercise in visible agony in order to demonstrate their repentance.

The second idea is that we are all in a competition when it comes to weight. Ours is a society full of people fighting against the forces in our food that are making us fatter. It is often painful to do this: you have to tolerate hunger or engage in extreme forms of exercise. It feels like a contest in which each thin person creates additional pressure on others to do the same. Looked at in this way, people on Ozempic can resemble athletes like the cyclist Lance Armstrong who used performance-enhancing drugs. Those who manage their weight without drugs might think, "I worked hard for this, and you get it for as little as a weekly jab?"

We can't find our way to a sane, non-toxic conversation about obesity or Ozempic until we bring these rarely spoken thoughts into the open and reckon with them. You're not a sinner for gaining weight. You're a typical product of a dysfunctional environment that makes it very hard to feel full. If you are angry about these drugs, remember the competition isn't between you and your neighbor who's on weight-loss drugs. It's between you and a food industry constantly designing new ways to undermine your satiety. If anyone is the cheat here, it's that industry. We should be united in a struggle against it and its products, not against desperate people trying to find a way out of this trap.

Source: The Irish Times (Magazine), 4 July 2024, Author Johann Hari

Note: This article first appeared in the New York Times.