Washington, Feb 4 (IANS) Researchers have stumbled upon the secret of painless fat burning, says a new study.

The target in this case is an enzyme that indirectly controls the activity of what researchers refer to as the 'energy master switch.'

It boils down to this: When you give mice a chemical that blocks the function of the enzyme known as Fyn kinase, they almost immediately begin burning more fat.

'When there is an imbalance between what we eat and what we burn,' the outcome is obesity, said Claire Bastie of the Albert Einstein College of Medicine and Neuroscience.

'And the problem of obesity is not going away. This is a new mechanism to help the body to burn extra energy.'

Bastie's team earlier showed that mice lacking Fyn kinase altogether burn more fatty acids and expend more energy to become leaner.

They also showed other metabolic improvements, including increased insulin sensitivity. Those effects were the result of higher levels of the master energy switch AMPK in their fat and muscle tissue.

Those findings suggested that the enzyme might offer a useful target for a new kind of weight loss drug.

Now, researchers bolstered that idea by showing that chemical inhibition of Fyn kinase with an experimental drug known only as SU6656 does have considerable metabolic benefits for mice.

Ultimately, the animals appear to become increasingly fit as they lose fat and keep lean, says a release of Albert Einstein.

These findings appeared in the February issue of Cell Metabolism.