Professor Dean Ho of the National University of Singapore’s Yong Loo Lin School of Medicine has turned his own body into a long-term scientific experiment designed to explore how health changes between conventional medical check-ups. The project, known as DELTA, combines physiological measurements with information about diet, sleep, exercise and fasting. Ho, 47, wore three devices – Whoop, Garmin and Apple Watch – for around eight months while researchers continuously monitored changes in his body. His regimen included approximately 20 hours of fasting each day, several 48-hour fasts, around 90 minutes of strength or cardiovascular exercise every morning and a Mediterranean-inspired diet centred on leafy vegetables, seeds, olive oil and lean protein. The study was published in the peer-reviewed journal PLOS One in August 2026 and, importantly, is an N-of-1 study, meaning Ho is its sole participant.
Researchers reported several notable changes during the experiment. Ho’s metabolic switching time – how quickly his body shifts between using glucose and fat as an energy source – improved from more than 24 hours to around 16.5 hours. His resting heart rate fell from 65 to 46 beats per minute, while his sleep increased from roughly five hours to nearly eight hours a night, with more deep sleep and less time awake. One of the most striking results came from a custom AI system developed by the research team, which estimated Ho’s biological age at around 32 – almost 15 years below his chronological age. That figure, however, should not be interpreted as proof that he literally reversed ageing by 15 years. It is an estimate produced by a model analysing physiological and molecular responses, while biological age itself does not have a single universally accepted measurement.
This distinction is particularly important because the experiment involved only one person. The results provide detailed information about how Ho’s own body responded to the interventions, but they do not demonstrate that another person following the same fasting, exercise and dietary routine would achieve similar outcomes. The researchers themselves describe DELTA as a foundation that could help design larger human trials rather than evidence for a universal anti-ageing programme. The broader significance of the project lies in its approach to preventive medicine: instead of relying solely on occasional health screenings, continuous data from wearables, biomarkers and AI could eventually help doctors understand how an individual’s body responds to stress, exercise, food and recovery over time.
