Researchers have said that pills could be developed in the future which is going to motivate those lazy people.
Scientists in China and Scotland have made a key discovery, which centres on the system that regulates physical activity levels, the Independents reported.
To make their discovery, researchers compared normal mice with those that had a mutation in a gene called SLC35D3, and found that it produces a protein that helps play a key signalling role in the brain's dopamine system, affecting the regulation of physical activity.
They found that mice having this gene had far fewer of this type of dopamine receptor on the surfaces of their brain cells, and were stuck within in the cell, leaving the signal process unable to function.
But when the affected mice were treated with a drug that was able to activate dopamine receptors, the problem was reversed and the mice became more active and lost weight.
The findings have been published in the 'PLOS Genetics' journal.