For years, wearable devices have relied on metrics such as heart rate, steps, calories burned and sleep scores to help users understand their health. Now, Zomato co-founder Deepinder Goyal believes a newly discovered biomarker could offer a far more precise window into how the body functions in real time. 

Goyal has announced a breakthrough from Temple, his health-tech venture, claiming the discovery of a biomarker called "Entropy" that measures the body's real-time metabolic cost — essentially the energy expenditure associated with simply being alive. 

In a detailed post on X (formally twitter), Goyal described Entropy as a live metric that can only be measured from the temple region of the head. According to him, the metric updates every second and is displayed on a scale ranging from 1 to 250. 

"The Temple team has made a breakthrough. We have discovered a biomarker, only readable on the temple region, and nowhere else, that measures the real-time cost of you being alive," Goyal wrote. 

Lower Entropy values indicate deeper states of rest, while higher readings reflect intense physical exertion. Goyal said the lowest scores have been observed among experienced meditators during deep practice, while the highest have been recorded in elite athletes operating at peak performance. 

A metric influenced by everyday life 

Temple claims Entropy responds instantly to a wide range of physiological and lifestyle factors. Sleep, stress, exercise, caffeine consumption, meals, cold exposure, meditation and strength training can all influence the score by altering the body's metabolic activity. 

The company positions Entropy as a more comprehensive measure of metabolic demand than traditional heart-rate tracking. 

To support the claim, Goyal said Temple benchmarked Entropy against a metabolic cart, a laboratory-grade calorimeter widely used to measure energy expenditure. Across more than 100 cardio sessions, Entropy reportedly achieved a correlation coefficient of 0.93 with calorimeter readings, compared with 0.55 for heart rate. 

Two numbers that matter 

Goyal highlighted two key aspects of the metric: Entropy Maxima and Entropy Minima. 

Entropy Maxima represents the highest level a person's body can reach during intense effort. According to Temple, a higher peak reflects greater physical capability and resilience, making it a metric users should aim to improve over time. 

Entropy Minima, meanwhile, captures the body's lowest metabolic cost during rest. Goyal argued that lower resting metabolic expenditure has historically been associated with longevity across various species, suggesting users should work to reduce this number through healthy habits and recovery. 

A new approach to personal health tracking 

While the scientific community has yet to independently validate the claims surrounding Entropy, the announcement signals Temple's ambition to move beyond conventional wearable metrics and develop new ways of understanding human performance and health. 

Goyal described the experience of tracking Entropy as transformative, saying it reveals insights that existing health indicators often miss. 

The company has not yet announced a public launch date for the technology, with Goyal indicating that Temple intends to refine the product further before making it widely available. 

If validated through broader scientific research, Entropy could add a new dimension to the rapidly evolving world of health monitoring, where the focus is increasingly shifting from tracking activity to understanding the body's underlying physiological state in real time.