Entropy or hype? Temple's bold health claim meets a wall of scientific doubt

Deepinder Goyal said Temple has identified an 'Entropy' biomarker that tracks the body's real-time energy use. Doctors said the claim remains unproven without methodology, validation studies and peer-reviewed evidence.

In Short

• Temple displays a live score every second on a 1-250 scale
• The company says sleep, stress, food and exercise all affect it
• Goyal cited internal cardio tests against calorimetry to support accuracy

Zomato and Eternal founder, billionaire Deepinder Goyal has spent months wearing a small device called Temple on the side of his head. Now, he has made a claim that could reshape how people think about health, fitness and ageing – or spark a major scientific debate.

According to Goyal, the team behind Temple has discovered a new biomarker called “Entropy”, a number that supposedly measures the body's “real-time cost of being alive”.

The announcement immediately grabbed attention. If true, it could offer a window into how hard the body is working at any given moment. But many doctors and scientists say there is a long distance between an exciting idea and a scientifically proven health metric.

In a LinkedIn post, Goyal described Entropy as a live score that updates every second on Temple’s home screen. The scale ranges from 1 to 250.

According to the company, a score of 1 represents the deepest state of rest they have recorded, achieved only briefly by highly experienced meditators. At the other end, a score of 250 reflects the peak output seen in elite athletes during intense performance.

In October last year, Goyal had committed $25 million from his personal wealth to expand his longevity venture, Continue Research. The project aims to explore ways to extend human life and improve overall health through research on ageing, nutrition, sleep, and mental wellness.

THE BIG PROMISE

The latest claim is ambitious. Temple says everything influences Entropy- sleep, stress, exercise, food, caffeine, meditation and even cold-water exposure. The number, according to the company, reflects changes in metabolism and the body's energy expenditure in real time.

Goyal also argued that Entropy is far more accurate than heart rate when it comes to measuring the body's metabolic state.

He cited internal testing against a metabolic cart, a laboratory device used to measure energy expenditure, claiming that Entropy closely tracked the calorimeter's readings during more than 100 cardio sessions.

The company further suggests that two numbers could become important indicators of health. “Entropy Maxima” represents the highest level the body can achieve during exertion, while “Entropy Minima” reflects the body's resting state. A higher maximum, Goyal suggested, signals greater physical capability, while a lower minimum may be associated with longevity.

It is a compelling story: one number showing how much energy your body is spending every second, potentially revealing insights about fitness, recovery and ageing.

But that is exactly where sceptics begin asking questions.

MISSING EVIDENCE

Hyderabad-based senior neurologist Dr Sudhir Kumar told India Today the concept is intriguing, but the evidence presented so far falls short of proving the claims being made.

“The idea of developing a novel physiological metric from signals recorded over the temple region is certainly intriguing, and advances in wearable technology have the potential to improve our understanding of human physiology. However, extraordinary claims require extraordinary evidence,” he said.

Dr Kumar pointed out that what has been shared publicly appears preliminary and cannot yet establish Entropy as a validated biomarker for metabolism, health, longevity or biological ageing.

The neurologist noted that showing a correlation with calorimetry during exercise is only an initial step. A single statistical relationship does not automatically prove that a measurement is accurate, reliable or clinically useful.

According to him, critical information remains unavailable. The biological basis of the metric, the methodology used to derive it, validation studies and peer-reviewed scientific data have not yet been publicly released.

The temple region, where the device is worn, contains blood vessels, muscles, skin structures and nerve fibres. Signals collected there may indeed reflect physiological changes linked to stress, exercise or metabolism.

However, Dr Kumar stressed that detecting a signal and proving the existence of a new biomarker are two very different things.

He also warned about the danger of creating health scores that appear highly precise before they have been adequately validated.

“The key questions are not whether the signal changes with exercise, stress, or meditation, but whether it reliably measures what it claims to measure, whether it adds information beyond existing metrics, and whether acting on it improves health outcomes,” he said.

Those answers, he added, can only come from rigorous research, peer review and independent replication.

Other experts have been even more blunt. Neurologist Dr Rahul Chawala said the public announcement provides too little information for meaningful scientific evaluation.

“Nothing can be said based on this post – he has not revealed any methodology, what they are testing..just giving a fancy name..(We) need research and more details to comment,” he said.

Dr Chawala argued that bold claims without publicly available evidence should be treated cautiously. In his view, announcing a breakthrough before publishing research raises obvious questions about transparency and scientific scrutiny.

“Research? Evidence? Who cares,” he remarked, underscoring what he sees as a growing tendency in the technology world to generate excitement before presenting proof.

His criticism reflects a broader concern among scientists: innovation can move quickly, but science moves through verification. A claim may sound revolutionary, yet it still requires years of testing before it earns acceptance.

Meanwhile, in response to a query by India Today, Temple stressed that the evidence will be published before the public launch of the device, and there are reputed third party international institutes conducting studies to validate its claims.

"We will publish internal whitepapers soon, and these external studies will be submitted to journals for peer review," said a Temple spokesperson.

- Ends