Diabetic teen equipped with glucose sensor and Freestyle Libre scanner which can just be flashed at the sensor on the back of arm to instantly measure blood sugar levels. BSIP | UIG | Getty Images

Aaron Neinstein, MD, is Assistant Professor of Medicine at the University of California, San Francisco, and Director of Clinical Informatics at the UCSF Center for Digital Health Innovation. He's also a practicing endocrinologist. Let's start with a prediction: By 2025, everyone with diabetes will be tracking their blood sugar with devices called continuous glucose monitors, and it will be common for many people without diabetes to dabble in tracking, too. This may sound like a bold statement coming from an endocrinologist (we're the specialists who manage diabetes), but hear me out. In my practice, I primarily treat people with diabetes, and over the years, technology to help manage the disease has made remarkable strides. People with diabetes now have alternatives to pricking their fingers with a sharp needle to measure their blood glucose level multiple times per day. Early continuous glucose monitoring systems — the first was released in 1999 by the medical device maker Medtronic — while helpful in some cases, were not widely used because they were painful to insert, bulky, inaccurate, very expensive and still required many calibrations every day with fingersticks. The technology has improved dramatically. Two of the newest devices, the Dexcom G6 and Abbott Freestyle Libre , no longer require fingerstick calibrations, are FDA-approved for people to make insulin-dosing decisions, and are much easier to insert. Anybody who has ever done a fingerstick blood glucose knows that it hurts. Inserting a device instead is much less painful than a fingerstick, and the needlestick happens much less frequently. Both devices transmit glucose levels to a smartphone, either wirelessly and continuously, or with a wave of a smartphone over the sensor. Accordingly, continuous glucose monitoring (CGM) use has increased in Americans with type 1 diabetes, from 6 percent in 2011 to 38 percent in 2018. I expect these technologies to continue to get even better — they will get smaller, more accurate, and even smarter as better algorithms are developed and collaborations from between the device companies and tech companies like Alphabet or Apple. This is a positive trend. For the approximately 1.5 million Americans with type 1 diabetes, CGM has moved far beyond novelty and should represent standard of care. But, I believe CGM has much larger potential. That includes people with type 2 diabetes (approximately 30 million American adults), the even larger group with pre-diabetes (approximately 81 million American adults), and potentially almost anybody.

Feedback is powerful

I recently saw a 70-year-old patient with type 2 diabetes and heart disease who takes a medication known as metformin to manage his condition, but he has resisted making any changes to his diet. When he saw his own data from a glucose monitor, with no explanation even needed from me, he immediately identified the daily morning spike in his blood glucose level, and also its source: His daily glass of orange juice and banana. If he had instead done a fingerprick, he wouldn't have been aware of these large glucose spikes. (I shared the data with his permission).

Data that shows blood sugar spikes Aaron Neinstein

The patient then cut these items from his diet and reported an immediate improvement in his blood sugar levels. Another patient case is a 37-year-old man without diabetes. He noticed, by wearing a continuous glucose monitor for a while, that a particular soup from a particular hospital cafe caused a surprisingly sustained elevation in glucose. I can report that this person has taken this feedback seriously, because this person is… well me. Do I have diabetes? No. But I decided to wear the device to both to help me understand the experiences of my patients (which I embarrassingly chronicled here in 2012), and because I have a history of borderline high cholesterol. Between my cholesterol levels and these data, I decided that my metabolism and insulin resistance levels were likely putting me at higher risk for heart disease, so I immediately made substantial changes in my diet.

Looking at blood sugar trends with a continuous glucose monitor. Aaron Neinstein

These two examples show how immediate feedback is powerful. And this applies even for people who do not have diabetes but may have risk factors for diabetes, such as being overweight, or having a family history of the disease. There is no proven benefit to everyone using a continuous blood sugar tracker all the time — but, I think we will soon discover that many people can benefit from using it at least for a short period. As in the examples above, people can quickly gain valuable insights on the health impacts of lifestyle choices, including food, stress levels, sleep amounts, and activity levels.

So what do we need next?