Give children water not fruit juice is the stark new advice for parents.
Government advisor Professor Susan Jebb has warned that fruit juice contains just as much sugar as Coca-Cola and should be banned from the dinner table and ultimately, children's diets.
Prof Jebb told the Sunday Times that current health advice - that a glass of fruit juice a day counts towards one of your five a day - should be changed.
"Fruit juice isn't the same as intact fruit and it has as much sugar as many classical sugar drinks," she explained.
"It is also absorbed very fast, so by the time it gets to your stomach your body doesn't know whether it's Coca-Cola or orange juice."
There's growing concern about the high sugar content in fruit juice. One school head in Dagenham has written to parents asking them not to include fruit juice boxes in their children's lunches. Instead, the school recommended that children should only be allowed to drink water.
The debate about whether fruit juice should be classed as a healthy option is not a new one. In 2013, US scientists warned about the 'danger' of high sugar content found in fruit juice and smoothies. A study by Dr Robert Lestig in the British Medical Journal found that fruit juice was associated with increased risk of Type 2 diabetes.
So what does this mean for your child?
"The simplest way to put it is: eat whole fruit, don't drink juice," is the blunt advice from What To Eat author Joanna Bylthman.
Professor Jebb suggests parents "swap [the juice] and have a piece of real fruit. If you are going to drink it, you should dilute it."
However, Azmina Govindji, a dietician at the British Dietetic Association, says portion size is the key to the healthy consumption of fruit juice. "150ml of fruit juice is perfectly acceptable as one of your five-a-day."
It's also recommended that children should only drink fruit juice with a meal, to avoid a quick rise in blood sugar.
Six big family moments that matter – and the products that make them easier to navigate
These products from John Lewis & Partners help support the memorable moments of family life.