Signpost: Your watch will tell you what to eat

The most advanced health tracker in your life may no longer be in your doctor’s office or even on your smartphone. It is increasingly likely to be strapped to your wrist.

Samsung has made the most serious leap yet from casual fitness companion to what borders on a medical device with the new Galaxy Watch8. Except, this is a medical device that tells you when to stop eating chocolate.

Among the many announcements at Samsung’s Galaxy Unpacked event in New York on Wednesday, streamed live to a local launch in Johannesburg, it was the watch rather than a new range of foldable phones that delivered the most startling new capability. The Z Fold 7 series is remarkably thin, but then so are other foldables.

With the debut of an Antioxidant Index, the Galaxy Watch8 becomes the first mainstream smartwatch to offer real-time measurement of carotenoid levels in the skin. These levels, linked to oxidative stress and dietary health, provide early insight into how lifestyle choices impact long-term health.

“I was playing around with this in Korea, and I got an incredibly low measure,” says Justin Hume, Samsung’s vice president for mobile in South Africa. “I was quite surprised by that, relative to somebody who was with me who was more overweight and didn’t exercise. It came down to food and the coffee consumption I was taking in.”

The moment of biofeedback led to small but lasting changes, Hume told Gadget last week. “It prompted me and I made some changes, and yes, I actually felt better.”

_{Photo courtesy Samsung.}

It turns out that this may well be one of the few wearables that provide a metric compelling enough to alter behaviour with both guilt and data.

The Galaxy Watch8 also features vascular load monitoring, circadian rhythm-driven bedtime guidance, and a sleep apnea detection system. In one device, it blends preventative indicators with live coaching, promising a “holistic view” of wellness.

Samsung’s BioActive Sensor makes these new features possible. It is paired with the watch’s redesigned casing and internal structure to deliver a slimmer, more comfortable fit. The thinner design and brighter 3,000-nit display also speak to a broader understanding: health metrics only matter if the watch stays on your wrist.

Sleep, the most essential of health metrics, takes centre stage with a raft of new features, including circadian rhythm mapping and bedtime nudging. It sounds intrusive, but it reflects a growing shift in wearables away from post-hoc reporting and toward proactive coaching.

The most substantial shift is probably Samsung’s decision to build Gemini, Google’s generative AI assistant, into the watch. It brings conversational control to workouts and goal setting, allowing users to talk to their watch in everyday language.

“In Covid, I did what many did, I built a gym in my garage,” says Hume. “So now I get home and I want to do some sort of exercise, but I’ve only got barbells and dumbbells. I can talk to Gemini and say, ‘This is what I’ve got, set me a 30-minute gym routine.’ And it works pretty well.”

_{Photo courtesy Samsung.}

That crosses the line between personal trainer and personal assistant, especially as Gemini also handles scheduling, messaging, and location-based tasks. It sets it apart from other smartwatches, and raises the question: do we call this a smart-smartwatch?

But with advanced AI comes renewed scrutiny. Health data, particularly when derived from continuous biometric tracking, carries sensitive implications. The more the Galaxy Watch acts like a diagnostic tool, the more it needs to meet clinical standards

“We get the most stringent approvals before we release,” says Hume. “The ECG was tested with Johns Hopkins University Hospital in the US. Galaxy Watch gets tested by local partners like Discovery in South Africa.”

He claims the watch achieved 98% accuracy on blood pressure testing, higher than the cuffs used in many GP practices.

It’s easy to dismiss all this as wearable tech noise. But eventually, enough data, accuracy and usability converge to change how people manage their health. And it is not intended to replace doctors.

“You’re able to walk in as an informed consumer to your doctor, because you have a lot of that information now at your fingertips, whether it’s your blood pressure, ECG, and now we’ve got vascular load as well.

“Step by step, that integration is going to keep getting smarter.”

* Arthur Goldstuck is CEO of World Wide Worx and author of The Hitchhiker’s Guide to AI