Fat has a reputation as public health enemy number one. But is it really the devil we think? Recent headlines suggest that we may have got it all wrong, and that fat may not be as bad as we've long believed.
Dr Saleyha Ahsan cuts through the confusion and reveals the surprising science of fat.
She discovers that eating fat isn't the only culprit behind the nation's ever-expanding waistline and investigates some startling new research that suggests some saturated fats might even be good for our health.
A group of nine volunteers take Salehya's Big Fat Challenge to investigate the strange things that happen to our body and mind if we stop eating fat entirely.
And Saleyha discovers the fat hidden in sea water that could make the food of the future a lot healthier.
This programme shows how we can be smarter about fat if we know which ones we should really be eating and how much is good for us.