Sharp’s first smartwatch revives the automatic calorie tracking debate

Sharp has announced Karada Mate Watch and Karada Mate Ring, two new health wearables launching in Japan next month. The watch is the odd one, because it claims to estimate calorie intake automatically using HEALBE technology, the same idea behind the GoBe band I reviewed a few years ago and remained sceptical about.

The calorie claim is the story

The calorie tracking system relies on bioelectrical impedance data to estimate calorie intake from changes in the body after eating. So nothing for you to enter, it is all automatically calculated for you.

The watch does not identify food on your plate or instantly know what you ate. It tries to estimate absorbed calories after the body reacts to food, which means the result is more of a delayed estimate than a live meal counter.

Sharp says the watch can compare calorie intake with calorie burn, then show whether the user is drifting into surplus or deficit. At least that’s the idea. Most people do not want to weigh food or manually enter every snack.

This brings GoBe back into the conversation

GoBe also promised automatic calorie intake tracking through the body rather than through manual logging. Sharp’s watch uses the same broad concept, but places it inside a more normal-looking smartwatch with Sharp branding and a broader health app around it.

That makes Karada Mate Watch more interesting than GoBe in one sense. It has a better chance of looking like a regular wearable rather than a single-purpose gadget with a strange claim attached.

Still, the same caution applies. This should not be treated as a precise calorie counter until independent testing proves it.

Sharp also makes the wear requirement clear. Users need to wear the watch for 22 to 23 hours per day for calorie intake and calorie burn tracking. That is a big ask, especially when battery life is listed at around 2.5 days.

The watch specs are fairly normal

The rest of Karada Mate Watch looks like a standard health smartwatch. It has a 1.32-inch OLED display with 466 x 466 resolution, always-on display support, GPS, optical heart rate, SpO2, skin temperature, bioelectrical impedance, motion sensors, barometer, compass and light sensor.

The body measures around 42 x 42 x 9.4mm, with a listed weight of about 33 grams. Sharp uses stainless steel, Gorilla Glass 5 and standard 20mm straps, so the design sounds more wearable than the calorie claim might suggest.

Water and dust resistance also look decent. Sharp lists 5ATM, IPX8 and IP6X, and says the watch can be washed with domestic foam-type hand soap under its stated conditions.

The price is ¥59,400 in Japan. That puts it well above basic fitness trackers, so the automatic calorie feature needs to carry the pitch.

The ring plays a different role

Sharp also announced Karada Mate Ring, model MH-R01. This is not the calorie-tracking device. It is the easier, lower-maintenance wearable for sleep and baseline health tracking.

The ring uses sensing technology from SOXAI, the Japanese smart ring company. It tracks heart rate, SpO2, skin temperature, activity and sleep, with data shown in the Karada Mate app.

The hardware looks competitive on paper. Sharp lists a titanium exterior, Duratect coating, 6.7mm width, 2.8mm thickness and a weight of 2.1 to 3.1 grams depending on size. Battery life is up to 14 days, which is far stronger than the watch.

The ring costs ¥41,800 in Japan and comes in gold and silver. Sizes run from 4 to 13.

The important point is that Sharp has split the roles clearly. The watch carries the unusual HEALBE calorie feature. The ring handles the familiar smart ring job of continuous tracking, especially sleep.

Sharp’s move into wearables is interesting because it does not start with another sports watch or another sleep ring clone. It starts with a risky nutrition claim and a companion ring that makes the Karada Mate brand feel more like a small ecosystem.