Sometimes the smell of something delicious is all that's needed to get the tummy rumbling - pizza, hot chips, or cookies straight out of the oven.
But surprising new research shows the sense of smell might be just the thing to stop you grabbing a bite.
The study, published in the Journal of Marketing Research, shows that while a quick whiff of fries will entice your appetite, a prolonged exposure to it will be enough to trigger a reward system in the brain that deems the craving as satisfied.
After breathing in the scent for two minutes, our brain thinks we've snacked on something tasty... without the calories.
Scientists from the University of Florida conducted the research on more than 900 students in a US school canteen.
They found participants exposed to the smell of cookies for less than 30 seconds were more likely to want a cookie. But, those exposed for longer than two minutes, didn't find that cookie desirable, and picked strawberries instead.
They had the same results when the scent of pizza and apples were tested.
"Ambient scent can be a powerful tool to resist cravings for indulgent foods," says one of the researchers, Dr Dipayan Biswas.
"In fact, subtle sensory stimuli like scents can be more effective in influencing children's and adults' food choices than restrictive policies."
While further testing is needed you can still put their findings into place when it comes to your own diet. If you're craving a large pizza, try sitting in a pizza shop for two minutes to see if it curbs your cravings.