How the Glucose Monitor Became a MAHA Fixation

The Atlantic

8 hours ago

To hear some of them tell it, the companies selling continuous glucose monitors have stumbled upon a heretofore unknown quirk of human biology. Seemingly healthy people, many of these companies argue, have 'glucose imbalances' that need to be monitored and, with dietary vigilance, eradicated. Millions of people are going through life eating bananas, not knowing that their blood sugar is rising with every bite. This must be stopped.
To this end, the companies market the continuous glucose monitor, or CGM, a quarter-size sensor that takes a near-constant measure of the glucose in the fluid between a person's cells. Once inserted into an arm, the sensor allows the wearer to monitor their blood-sugar levels on a phone app for $80 to $184 a month. Doing so allows you to 'see the impact of what you eat' (according to the start-up Lingo), to 'motivate behavior change and encourage healthier choices' (according to another called Levels), and to 'personalize your approach' to weight loss, because 'everyone's journey is different' (according to Nutrisense).
The gadgets have been revolutionary for many people with diabetes—previously the main available device for measuring blood sugar required users to prick their fingers multiple times a day. Many insurers cover CGM prescriptions for diabetics; they can pick up the devices at the pharmacy just as they would blood-test strips. But when I asked a half dozen experts whether people who don't have diabetes should wear CGMs, I got a resounding 'Meh.' 'It's a free country. People can pay money for whatever they feel like doing,' David Nathan, a diabetes expert at Harvard, told me. 'But from a medical point of view, I am personally unconvinced that they lead to any health benefit.'
Relying on a Harvard diabetes expert to give you diabetes advice, however, goes against the general ethos of the 'Make America Healthy Again' movement, many of whose members have been heavily promoting CGMs in recent months, including to people who don't have diabetes. Robert F. Kennedy Jr., the secretary of Health and Human Services, talked them up in an April CBS interview as 'extraordinarily effective in helping people lose weight and avoid diabetes.' At his Senate confirmation hearing, before becoming Food and Drug Administration commissioner, Marty Makary said glucose monitors help people 'learn about what they're eating.' Casey Means, the wellness influencer whom President Donald Trump nominated for surgeon general, has said that more Americans should use CGMs too. (As it happens, she is a co-founder of Levels.) 'I believe CGM is the most powerful technology for generating the data and awareness to rectify our Bad Energy crisis in the Western world,' Means wrote in her best-selling book, Good Energy. (Bad Energy is her term for the metabolic dysfunction that she believes to be at the root of many chronic health problems.)
The devices are emblematic of the self-reliance that characterizes the MAHA movement. 'The Casey Means's of the world,' Alan Levinovitz, a James Madison University religion professor who has studied alternative health, told me in an email, 'are using the rhetoric of naturalness as a way of telling people they can have complete control and expertise over their own health—which is the natural way to be healthy, rather than outsourcing that wisdom to top-down elites.' Indeed, one of the chapters of Good Energy is titled 'Trust Yourself, Not Your Doctor.' (Means did not respond to a request for comment.)
CGMs appear to have trickled into MAHA world from the Joe Roganosphere, helped along by the fact that the devices, which in the past had been prescribed mainly to diabetics, were made available last year for purchase over the counter—that is, by anyone. Five years ago, Paul Saladino, a doctor who promotes an ' animal-based diet,' said on Rogan's podcast, 'This is the kind of stuff that really tells you about your metabolic health. There's no way to lie with a continuous glucose monitor.' Since then, CGMs have been endorsed on popular wellness podcasts such as Andrew Huberman's Huberman Lab and Dave Asprey's The Human Upgrade, and by pop-health doctors such as Peter Attia and Mark Hyman, the latter of whom called the CGM 'a gadget that has completely changed my life.' A wellness influencer known as the Glucose Goddess said that although they may not be for everyone, CGMs can be 'a pretty incredible tool to start to connect what you're eating with what's actually happening inside of your body,' and offers a guide to them on her website. Gwyneth Paltrow, the empress of Goop, was recently spotted wearing one.
Sun Kim, a Stanford endocrinologist, told me that a few years ago, 'I was literally contacted by a start-up almost every month who wanted to incorporate a CGM' into their products. Of course, some CGM companies do specialize in people who have diabetes and need around-the-clock monitoring. But Kim and others I spoke with told me they suspect that, to boost sales, CGM manufacturers are trying to expand their potential-customer base beyond people living with diabetes to the merely sugar-curious.
Jake Leach, the president of Dexcom, maker of the over-the-counter CGM Stelo, told me via email, 'Stelo was originally designed for people who have Type 2 diabetes not using insulin and those with prediabetes, however, given the broad accessibility of this device, we are encouraged to see people without diabetes interested in learning more about their glucose and metabolic health.' A spokesperson for Dexcom pointed out to me that most people with prediabetes are undiagnosed. Fred St. Goar, a cardiologist and clinical adviser for Lingo, told me in a statement that CGMs can be beneficial for nondiabetics because 'understanding your body's glucose is key to managing your metabolism, so you can live healthier and better.'
Scant research exists on how many nondiabetic people are buying CGMs, but anecdotally, some providers told me that they are seeing an uptick. Nicola Guess, a University of Oxford dietician and researcher, said that '10 years ago, no, I never saw anyone without diabetes with a CGM. And now I see lots.' Mostly, she said, they're people who are already pretty healthy. In this sense, CGMs are an extension of the wearables craze: Once you have an Oura Ring and a fitness tracker, measuring your blood sugar can feel like the next logical step of the 'journey.'
Should people who aren't diabetic wear one of these? Health fanatics who have $80 a month to burn and want to see how various foods affect their blood sugar are probably fine to wear a CGM, at least for a little while. Spoiler: The readout is probably just going to show that eating refined carbs—such as white bread, pasta, and sweets—at least temporarily raises blood sugar to some degree.
Normal glucose patterns for nondiabetic people tend to vary quite a bit from meal to meal and day to day. Most nondiabetics' blood-sugar readings will typically fall within the 'normal' range of 70 to 140 milligrams per deciliter. But many healthy people will occasionally see spikes above 140, and scientists don't really know if that's a cause for concern. ('Great question' is a response I heard a lot when I asked.) In the studies he's worked on, Kevin D. Hall, a former National Institutes of Health nutrition scientist, has found that even in tightly controlled settings, people's blood-sugar levels respond very differently to the same meal when eaten on different occasions. Given all these natural deviations, a CGM may not be able to tell you anything especially useful about your health. And CGMs can be less accurate than other types of blood-sugar tests. In another study, Hall and his co-authors stuck two different brands of CGM on the same person, and at times, they provided two different blood-sugar readings. The conclusion, to Hall, was that more research is needed before CGMs can be recommended to nondiabetics.
What's more, blood sugar depends on sleep, stress, and exercise levels, and whether any given meal includes protein or fat. If you notice a spike after eating a banana, the banana might not be the reason. It might be the four hours of sleep you got the previous night, because sleep deprivation can affect the hormones that influence blood sugar. As a result, Guess said, 'a CGM cannot tell you whether a single food is right for you'—though some CGM enthusiasts make this promise. (A CGM can help you 'learn your reaction to individual foods and meals,' Means has written.)
For some people, tracking data does help nudge them toward healthier behaviors. If you get a clear readout from a CGM that your blood sugar has risen after you've eaten refined carbs, and it moves you to eat fewer refined carbs, that's not necessarily a bad thing. But researchers haven't found evidence yet that nondiabetic people eat better after wearing a CGM. And if you know how to read a CGM, you probably already know what a healthy diet looks like. You could just eat it. Anne Peters, a diabetes researcher at the University of Southern California, told me, 'You could just not wear it at all and tell yourself to eat more vegetables and a more plant-based diet and eat healthy, lean protein.'
Many of the biohackers who talk up CGMs also promote a low-carb, protein-heavy diet that would include a T-bone more readily than a Triscuit. (Asprey, the man behind The Human Upgrade, recommends putting butter in coffee.) The potential downside of glucose monitoring is that people who are (perhaps needlessly) alarmed by their CGM data will swap out healthy carbs such as fruit and whole grains for foods that are less healthy—butter, for example, or bacon and red meat. Those foods don't make an impact on blood sugar, but they can affect other markers of health, such as cholesterol and body fat. Eat a stick of butter, and your CGM will probably show a flat, pleasant line. But your arteries may protest.
I noticed these perverse incentives myself during my pregnancy, when I had gestational diabetes and wore a CGM to manage my blood sugar. A bowl of heart-healthy oatmeal would cause my blood-sugar reading to soar to an unacceptable 157, but a piece of cheesecake—with loads of fat balancing out the sugar—would keep it safely under my goal level of 135. At the time, I wanted to eat whatever kept my blood sugar low, for the sake of my baby. But few dieticians would advise healthy people to eat cheesecake instead of oatmeal every morning.
Glucose, after all, is just a small part of the picture of human health. 'Waist circumference, blood pressure, LDL cholesterol, resting heart rate—they are much better measures of how healthy someone is than glucose,' Guess said. And watching a real-time readout of your blood glucose can become an obsession of sorts—not an entirely harmless one. 'Something being a waste of time is a net harm,' Guess told me. 'There is something unethical to me about filling people's heads with worries that never come to pass.'
Many of the researchers I spoke with said that if you are concerned you might have diabetes or prediabetes, you could just get an A1c blood test at your annual physical. Like a CGM, it, too, measures blood sugar, but much more cheaply and without requiring you to wear a device all the time. And if it shows that you're at risk of developing type 2 diabetes, you could do what doctors have suggested doing for decades now: Eat a diet rich in vegetables and lean proteins, and get some exercise most days. ('Duh,' Nathan said.)
One way for Kennedy and others in the Trump administration to find out if CGMs do all they say they do would be to fund studies on whether CGMs are helpful, and for whom. Quite the opposite is happening. Hall recently left Trump's NIH because he believed he was being censored when speaking about the results of studies that conflicted with Kennedy's views, and Nathan's diabetes-prevention study was recently frozen by the Trump administration. So far, the administration has ended or delayed nearly 2,500 NIH grants, including some related to researching blood glucose. If the Kennedy-led HHS department truly would like to make America healthy again, it could stop defunding the people studying Americans' health.