Scientists Discover Hidden Fat-Burning Mechanism That May Help Strengthen Human Bones

A hidden fat-burning system inside the body may hold the key to future treatments for rare bone diseases-and scientists have now discovered the molecular switch that turns it on.

Researchers at McGill University have identified a mechanism in brown fat that activates an alternative calorie-burning pathway, offering fresh insight into how the body generates heat and regulates energy. The findings, published in Nature, could eventually lead to new therapies for conditions linked to defective bone formation.

Unlike white fat, which stores energy, brown fat burns calories to produce heat when the body is exposed to cold. Scientists previously believed this process relied mainly on one biological system. But recent research uncovered a second energy-burning mechanism called the “futile creatine cycle,” though its trigger remained a mystery.

Now, the research team has identified the molecular “on switch” behind this pathway. The researchers found that glycerol — a molecule released when fat is broken down — binds to an enzyme known as TNAP through a specific region called the glycerol pocket. This interaction activates the alternative heat-producing system inside brown fat cells.

While the findings could influence future obesity and metabolic research, scientists believe the more immediate impact may involve bone health. TNAP plays a critical role in bone mineralization, the process that keeps bones strong and properly hardened.

Defects in the TNAP enzyme are linked to hypophosphatasia, a rare inherited disorder sometimes called “soft bones,” which can cause fractures, pain, and skeletal abnormalities. By studying TNAP mutations, researchers discovered that the same molecular switch affecting brown fat also influences bone-building cells.

Scientists have already identified dozens of potential drug candidates for future study. Researchers say the work offers a promising new direction for treating bone disorders while also deepening understanding of how the body controls energy and heat production.

REFERENCE: Mohammed Faiz Hussain, Shreya S. Krishnan, Brittany L. Carroll, Bozena Samborska, Aisha Mousa, Alice Williamson, Maria Delgado-Martin, Bindu Y. Srinivasu, Jakub Bunk, Janane F. Rahbani, Abel Oppong, Anna Roesler, Zafir Kaiser, Mina Ersin, Qiaoqiao Zhang, Maria Guerra Martinez, Abhirup Shaw, Jonathan Cheng, Hannah Klemets, Katalin Kocsis Illes, Victoria E. DeMambro, Clifford J. Rosen, José Luis Millán, Thomas E. Wales, Claudia Langenberg, Marc D. McKee, Alba Guarné, Lawrence Kazak. Glycerol-driven TNAP activation in thermogenesis and mineralization. Nature, 2026; DOI: 10.1038/s41586-026-10396-9