What wearing a CGM taught me about myself

Watching your own blood sugar for two weeks can be really illuminating

You can’t have failed to notice that wellness is splitting in two. On one side, a growing desire to switch off entirely, to tap into nature and stillness and nervous system reset, and on the other, a surge in optimisation, biohacking, diagnostics, wearables, and data. What both camps have in common is that they’re responses to the same underlying feeling that something in how we live feels out of balance.

I’ve spent the last two weeks firmly in the second camp, with a continuous glucose monitor stuck to my upper arm and an app tracking every spike, dip, and recovery in real time. What I learned surprised me. I’m not diabetic, and by most measures, my diet is pretty good. I cook whole foods, I’m conscious of what I eat, I’ve spent years building a relationship with my body through movement, Ayurveda, and a general attentiveness to how things feel. So when I went in, I wasn’t expecting big revelations.

A note: I’m a 43-year-old woman, and my takeaways are specific to my body, age, metabolism, and baseline habits. What stabilises my glucose will not necessarily stabilise yours.

First, what is a CGM?

A CGM is a small sensor on the upper arm that continuously reads glucose levels in the fluid just beneath the skin and feeds that data to an app in real time. This technology has existed for decades, by the way, and has been life-changing (and often life-saving) for people with severe diabetes. What’s changed recently is accessibility: several companies now sell CGMs directly to people without a diagnosis, positioning the device as a metabolic health tool rather than a medical one. We’ve seen a surge in people using them to support efforts to move, eat, and just live better. The options in India are reasonably varied. Abbott’s FreeStyle Libre is the most established and widely available, Ultrahuman’s M1 pairs a FreeStyle Libre sensor with an app built specifically for non-diabetics and oriented toward lifestyle insight rather than clinical management, which is why I ended up choosing it, GoodFlip is an Indian-made option delivering readings every three minutes at a more accessible price point, and Dexcom’s G7 is available for those who want clinical-grade accuracy.

It’s also worth introducing the Glucose Goddess here

Jessie Inchauspé, the French biochemist with five million followers, built her platform on the premise that glucose spikes are the central villain of modern health. A lot of her advice is both sensible and simple: meal sequencing, aka eating fibre and protein before carbohydrates, has evidence behind it, particularly for people with impaired glucose metabolism. A post-meal walk is well-supported, and the savoury breakfast recommendation is just good advice for everyone. However, her central premise, that glucose spikes are dangerous and must be minimised in healthy people, has been contested by multiple dietitians and endocrinologists who say that for generally metabolically healthy people, a post-meal rise is a normal physiological response. A mango will raise your glucose, but that doesn’t mean you shouldn’t eat mangoes (thank god, for mango season is upon us!).

None of this makes using a CGM a bad idea; it’s just worth noting as you embark upon any sort of biohacking adventure.

My learnings wearing the Ultrahuman M1

I started the sensor during a period of enforced rest, post-surgery and low movement, which turned out to be sort of useful because it gave me a floor to measure everything else against. The first night, I ate pizza at 8pm and watched my curve spike several hours later, which makes sense when you understand that fat slows gastric emptying, so the carbs from the dough hit the bloodstream late, the glucose equivalent of a delayed flight. While my body recovered fine, I could see exactly what had happened and when, and that visibility turned out to be quite the catalyst for the choices I made over the subsequent two weeks.

It’s cool to see your body respond to the food you’re eating in real time, so then I started experimenting. Ghee before psyllium husk in the morning produced no spike, but reverse the order, and there was one, because the fat creates a coating in the gut that slows everything that follows. Apple cider vinegar in water before a meal (drunk through a straw, protect your enamel!) visibly flattened the post-meal spike. Vegetables before protein before carbs: the same meal eaten in a different order produced a measurably different response, which is the part that seemed almost too simple to be true? Yet there it was on the graph.

A ten-minute walk after eating, or even slow laps around my dining table while taking calls, brought the curve back up and then down in a much gentler arc, because movement pulls glucose into the muscles before it has a chance to accumulate in the bloodstream. It’s the sort of thing you’ve heard, anecdotally, forever, right? “A gentle stroll after a meal…” and yet I’d always disparaged it as the sort of nonsense that doctors recommend to the aged and infirm. How very, very ignorant and wrong I was. Consider me schooled and grateful for the lesson.

The thing I didn’t expect: I thought I’d discover I was reactive to sugar, but what I actually discovered is that I’m much more reactive to processed carbohydrates. Instant noodles on a flight home produced the most dramatic spike I recorded across the entire two weeks, higher than ice cream, higher than rice, higher than anything else I ate. The reason is that processing strips out everything that would normally slow digestion, the fibre, the structure, the resistance, so what’s left hits the bloodstream almost immediately and all at once. Tequila, by contrast, barely registered because clean spirits temporarily suppress glucose production in the liver. This isn’t an endorsement, just what the data showed.

The night I slept three hours, my curve the next day was jagged regardless of what I ate, because stress, poor sleep, and cortisol are glucose drivers entirely independent of food, and it turns out a heated argument can trigger a glucose spike equivalent in metabolic terms to eating hummus and carrots. The body, it seems, does not distinguish between what kinds of things stress you out.

The lesson I’m keeping

The CGM didn’t change what I eat as much as it changed the architecture around eating, the sequencing, the timing, the walk after… small structural shifts rather than dietary overhauls. Those were the differences between a curve that looks like a mountain range and one that looks like a gentle wave. A more useful concept than spikes, and one the Ultrahuman app introduced me to, is glucose variability: not where your glucose sits on average, but how far and how frequently it rises and falls across the day, which shifts the focus from any single meal to the overall pattern, and is both more accurate and considerably less anxiety-inducing as a frame.

What actually reduces variability is fairly straightforward: protein and fibre at the start of a meal, movement after eating, and sleep, which matters more than most people expect because poor sleep raises cortisol, which promotes insulin resistance and pushes glucose higher regardless of what you’re eating. None of this requires a CGM to act on, but seeing it in real time makes the connection concrete in a way that simply knowing the advice never quite manages to.

The biggest benefit, and I genuinely didn’t anticipate this, is accountability, because seeing the data does something that knowing the advice doesn’t, and I’ve found myself snacking between meals less, thinking about food order more naturally and without it feeling like a rule I’m following, and eating more slowly, none of which are dramatic changes but all of which are real ones, and mine in a way that generic nutrition advice never managed to be.

One caveat worth naming: the potential pitfall of a CGM, like any tracking device, is that the data becomes a verdict rather than information, and if you find yourself anxious about a single rise, or avoiding foods you love because of a number on a screen, the device is working against you. Wear it with curiosity, take what you learn, and then put the thing down.

1,000 Ways to Live Well is a Mille publication. Mille is a modern nutrition brand built around everyday rituals, starting with protein that doesn't ask you to compromise on taste. millesupergrain.com