If you have an upset stomach, don't drink a glass of flat coke or lemonade it will only make it worse.
Health officials say the remedy is nothing but an old wives tale, and anyone suffering from a stomach ailment or bug should instead be rehydrating with a non-sugary drink.
If it's not treated properly, stomach ailments such as gastroenteritis can become serious problems, and around 40,000 children in the UK end up in hospital every year for emergency treatment for dehydration.
The UK's National Institute for Health and Clinical Excellence (NICE) says that giving people a flat coke or lemonade delayed proper treatment such as a rehydrating drink that is a mixture of salt and sugar and made the problem worse.
Parents should watch out for signs of dehydration if their children have a stomach problem that causes vomiting or diarrhea. Tell-tale symptoms include altered responsiveness, sunken eyes, pale or mottled skin and cold extremities.