It sounds too good to be true - you can burn calories and lose weight, even while you sleep.
Yet, a team of scientists have discovered for a lucky group of people, that dream is a reality.
They found the burning of calories overnight is driven by the microbes in our gut.
The team, from the University of Iowa, determined unhealthy changes to gut bacteria can trigger weight gain.
They hope their findings will lead to new treatments for obesity.
Study author Dr John Kirby, a professor of microbiology and urology, said: ‘Our research leads to the conclusion that it is probably bacteria (in the gut) that are responsible for the calories you burn while you are asleep. ‘
Dr Kirby and a team of researchers focused their study on the effects of risperidone – an antipsychotic drug that causes ‘significant weight gain’ in patients.
Risperidone is used to treat psychiatric disorders in adults and children, such as autism, bipolar disorder and schizophrenia.
Prescription rates for risperidone have ‘increased nearly eight-fold over the last two decades'.
photo credits: Wavebreak Media LTD/Lightwave/Corbis