That curiosity has cost Snyder about pounds 1,000 over the years. He has owned 10 different Fitbit devices, measures his weight on a fancy Wi-Fi-enabled scale, and had one of the first glucose monitors that plugged into a smartphone. Then there are the running watches, plus the two devices that measure his blood oxygen levels to indicate respiratory function. To test for triglyceride levels, he sends blood samples to a lab for analysis. He is even looking into a "cold thermogenesis kit" - a cooling vest that allegedly can help measure and burn brown (adipose) fat. He says, laughing: "My wife is the more extreme out of the two of us."
Snyder might seem quirky, even borderline obsessed, but he isn't alone. There is even a name for what he does - the Quantified Self (or QS for short) - a term that appears to have originated, unsurprisingly, in California. And it's a phenomenon that is growing.
QS is a self-awareness movement that involves using the latest sensors to track various aspects of a person's daily life, from finances to mood swings, to help inform behaviour change and improve quality of life. The theory goes that if tracking helps you understand your habits, you can improve them.
In recent years, the QS movement has become focused on fitness and health, largely driven by the glut of consumer fitness trackers such as Fitbit and Nike+ FuelBand hitting the market. Just last year, 70 million wearable tracking devices were sold worldwide. The App Store, too, is brimming with health, fitness and wellness tracking apps, while technology start-ups are cashing in with health-tracking smartphone accessories, such as Snyder's plug-in glucose monitor. Even the Government is getting on board, encouraging patients to use apps such as mood and diet trackers.
But it was the launch of the new Apple Watch in April, complete with heart rate and movement sensors, that really got digital health gurus salivating. The expectation is that wearables and smartphones will propel self-tracking into a new era that is set to change the way we think about our health.
Current mainstream devices tend to track four main areas - activity, mood, diet and sleep - but Snyder's experience highlights what is possible. He shows that a click of the mouse can pull up devices previously confined to the clinical setting, such as those that measure pulse rate, blood pressure, oxygen saturation, heart function and blood glucose. Then there are the lab services offering blood and hormone tests.
But is this influx of tracking devices and associated biometrics, as well as our growing appetite to quantify ourselves, becoming too extreme?
At a QS meetup group in Moorgate, London, Damien Blenkinsopp presents to a gathering of self-tracking aficionados. He discusses the results from a five-day water fast, when he tracked his ketones (a by-product of fat-burning) and blood glucose, using a blood test and electronic device four times a day. The 40-year-old IT entrepreneur plans to do the fast again, this time also tracking his fasting insulin response, immune system markers, inflammation and cortisol levels, all from blood tests sent to a specialised laboratory. Tracking, he says, can show if the fast is having the desired results - an immune system boost.
Snyder and Blenkinsopp might be at the extreme end of the self-tracking spectrum but their belief is that self-tracking provides information on how well the body is functioning and incentivises behaviour change (if measurements are unfavourable). Snyder, for example, says tracking triglycerides (a high level can increase the risk of heart disease) has shown how he can reduce them by removing highly processed foods from his diet.
However, just what your triglyceride levels mean and how much lowering them reduces heart disease is less clear, and there lies the problem. While self-tracking has the support of some doctors in that it empowers people to look after themselves, other GPs - about three-quarters, according to one survey - have expressed concern that patients may get confused about the types of metrics available and what results mean. Some claim self-tracking could lead to anxiety or incorrect self-diagnosis, potentially made worse by low levels of health literacy.
Other critics suggest the current devices don't produce meaningful or accurate information. One study found fitness trackers could be out by as much as 40 per cent when measuring the number of calories burnt, while last month Nike agreed to settle a lawsuit after US consumers alleged the firm misled them over the steps and calorie-counting accuracy of its Nike+ FuelBand. Data ownership and security of personal information kept online is another concern.
A few years ago, Snyder shared a printout of his tracked data with his GP. "I wanted them to understand my history," he says. He was perplexed with the response. "They were surprised with the amount of information, but they weren't able to process it in any way."
Herein lies the crux of the self-tracking conundrum. The health care system is crying out for people to be more responsible for their own health. But self-tracking is incompatible with our health care system, which is based on a sickness, not wellness model.
Still, the self-tracking phenomenon looks set to grow, with self-tracking clothing and implants on the horizon. Dr Liz Miller believes it is the future, giving the example of Type 2 diabetes, which is crippling health care systems. If everyone took their blood sugar levels regularly, they could see if they were creeping up and take action before it was too late, she says. "Tracking our own health data with gadgets that work seamlessly in the background is what will keep us healthy - and it's the only way we are going to contain health care costs."
