In his novel Super Sad True Love Story , Gary Shteyngart describes a future world in which people size each other up by way of something called an “apparat.” These highly advanced mobile devices contain personal profiles that are not made up of scattershot Facebook musings but rather highly specific data: weight, measures of LDL cholesterol, and hormone readings that determine whether a person is a HNWI (High Net Worth Individual) or an ITP (Impossible to Preserve). In the novel, the ultimate goal of such precise quantification is eternal life for the elect, which I suspect is pretty much always the ultimate goal of obsessive self-quantifiers, whether or not they admit it or even acknowledge it to themselves.

I am an obsessive self-quantifier, although not exactly by choice. Never more than an arm’s length away from me is a black, oval-shaped device called a continuous glucose monitor, or CGM, that looks something like a pager. All day and night it takes readings of my blood glucose level by way of a tiny sensor inserted in my body and plots them on a handy trend graph. I click a button to display the reading several times an hour and, less frequently, download the information to create a graph for my doctor. Fellow diabetics will recognize the math: Over 180 puts me in a foul mood, below 60 makes me panic. If I coast around 99 all day, I feel very HNWI. (Who ever said numbers were not emotionally loaded?)

As technology has gotten cheaper and sensors smaller, people have started to experiment with all kinds of “personal tracking” devices, routinely logging their running cadence, their sleep patterns, or their heart rates, for example. Diabetes is the perfect condition for such calculated self-improvement. Good health for a diabetic requires constant monitoring of blood sugar levels, which fluctuate throughout the day, depending on hormone levels and what you eat. “Constant monitoring” is the tune that makes the personal trackers sing.

A meeting of the Diabetes Technology Society this month focused on all the cool new apps available to diabetics. Apps such as Glucose Buddy and Diabetes Pilot allow you to enter glucose readings throughout the day that get turned into logs and graphs, and take into account useful information about carbs and exercise. These are not wildly more useful than what I can do with my CGM, and if you followed their plans thoroughly, you’d need a personal secretary to log and keep track of all the information streams. But the future promises more beautiful marriages, as companies such as Genesis Health and AgaMatrix work to incorporate blood sugar meters into the phones themselves. In press releases about the meetings, doctors seemed unabashedly giddy about the technology. Because this kind of self-tracking is connected to a serious chronic illness, it does not have the same uber-nerd or self-indulgent overtones of, say, wiring up to perfect your run. Once, while stretching after a run, I met a self-tracker on the trail. We got to talking about my diabetes, and I could swear he was a little jealous.

At the moment, the tracking devices aren’t perfect. The CGM is not always accurate and still needs to be calibrated with several daily blood tests on a normal blood glucose monitor. But a CGM is still pretty handy. For one thing, the device beeps when your blood sugar drops too low. Low blood sugar comes from taking too much insulin. It happens to Type 1 diabetics like me routinely, and it’s potentially dangerous. As your blood sugar drops, your body starts to burn fat and release ketones, which can send you into a coma or kill you. The only medicine you need is sugar—orange juice, Skittles, anything will do. And the beeping warns you to get some before it’s too late. It’s useful, critical even, and I should be grateful that such a device exists. But instead I’m only resentful that I’m forced to lead a life of constant self-monitoring.

For a smart person, I am shockingly imprecise. I hate lists, have no sense of direction, and cannot guess dates within even a five-year window. My mother had the foresight to get my wedding date engraved on the inside of my ring, so I don’t forget my anniversary. My children have to remind me every time that Pluto is no longer a planet. Over the years, I’ve turned this failing into a kind of life philosophy. I tell myself that excessive precision, especially in medical matters, is a fool’s way of getting control over the mysteries of the human body. I gravitate toward medical stories such as the one told by Mark Scholz in his recent book Invasion of the Prostate Snatchers . The screening test for prostate cancer, by quantifying a certain cancer indicator in the blood, has caused thousands of men—my father among them—to have operations they probably did not need. The test was effective at detecting cancer, but it could not distinguish between the lethal kind and the benign kind that grows slowly over time and never does any harm. The test, it turns out, was answering only half the question.

In the face of a frightening disease, numbers can be very soothing. But they sometimes obscure what you really need to know. Something like this is also happening with diabetes. For years doctors concentrated on keeping those blood glucose numbers down. Before I had my CGM, I pricked my finger and did a blood test several times a day, and recorded the data on messy logs I handed over to the doctor every few months. But a study last year found that tight blood sugar control does not reduce the risk of heart disease . In fact, the study had to be stopped because patients on tight control regimens died sooner. What kills diabetics is not the high blood sugar per se, but what it causes, namely, heart disease. So doctors have started to tackle that directly, by focusing on getting patients to take medication that helps prevent heart attacks.

There is no study that describes mortality outcomes for an otherwise healthy female Type 1 diabetic diagnosed at 33 (that’s me, and I’m in a rare category). For all I know, my blood sugar could be 100 or 120 or 160 all day and it would not make much of a difference. But the trend graph on my CGM has me hypnotized. If with iron discipline I can keep myself around 99, shouldn’t I try? After all, a 99 day leaves me delighted with myself; feeling almost as good as if I’d eaten a sundae, which I almost never do anymore.

When my doctor called me with the diagnosis several years ago, I was in a cheap motel in Alabama reporting a story. Immediately I ran to the lobby and put a quarter in a machine that spit out a handful of stale peanut M&M’s. At the time I knew nothing about managing blood sugar, but I sensed that this was the last time I would cleanly enjoy sweets, or any food, and I was correct. Now, a table of food is a mathematical equation: Half a cup of brown rice = 22 grams of carbs, plus one cup of corn = 36 grams, plus one apple = 14 grams, makes 72 grams total. At one unit of insulin for every 15 grams, that’s 4.8 units of insulin. If I eat another portion, I take another few shots of insulin. (Thank god for Calorie King , which lists grams for most foods, and my OmniPod insulin pump , which does the division and delivers the insulin.) In the early days, I would eat whatever I wanted to, guess on the insulin shots, and hope for the best, conveniently “forgetting” to test my blood sugar two hours after the meal. But now I have the CGM machine, and it never shuts its eyes. That nice Starbucks Frappuccino will show up on the screen as a frantic double arrow climbing ever higher, reminding me of my sin. It lets me know constantly that, for me, there is literally no such thing as a free lunch.

As I grow older, the disease gets worse in many respects, and I will become more dependent on the machine. I used to have the ability to sense my blood sugar dropping, and it was disorienting but not altogether unpleasant—I’d taste metal on my tongue or lose my place in a sentence. Teenage diabetics often run low on purpose because they like the fizzy high. But now I’ve lost that sensitivity and feel nothing until I am dangerously low. Out of nowhere, I suddenly feel sauna hot and my mind goes blank. It’s something like being a stupefied child trapped in a burning house and forgetting where the front door is. A candy could be inches away, and I might just stare at it, immobile. It was after I fainted once that I got myself the CGM. Now two loud beeps scream in warning: EAT CANDY.



I used to say that managing diabetes was an art, not a science. I think I actually said this to my doctor once, and she restrained herself from pointing out what an ignoramus I was. Diabetes is at some level simple math, and it’s more practical to have accurate tools. This does not mean I believe I am “conquering” my disease or prolonging my life. Who knows? So long as I am reasonably controlled, the rest seems out of my hands. The best I can hope for is that one day, when we are all hooked up to sensors and graphing our every move, I can say I was there first.

Slate is looking for great ways that we can collect and analyze data to improve our lives. You can submit your idea from now through Friday, Dec. 3. We’ll be tracking your most interesting ideas throughout the month. And don’t forget to vote on the proposals you like best. In early December, we’ll take a closer look at the three top-vote-getting ideas and write about them.