Report by ITV News Health Editor Rachel Younger
Children are consuming half of their daily sugar allowance during breakfast alone, health officials have warned.
The average child in England eats the equivalent of three cubes of sugar (11g) every morning, Public Health England (PHE) said.
Sugary cereals, fruit juice and some spreads are to blame, according to the health body's new Change4Life campaign.
Free app - Be Food Smart - has been launched to help highlight how much sugar, saturated fat and salt can be found in everyday food and drink that children consume.
But what breakfast foods are the worst culprits and how can you cut your child's sugar intake down? Here's what you need to know.
How much sugar should children eat?
The recommended daily maximum is five cubes of sugar for four to six-year-olds and six cubes for seven to 10-year-olds.
Children aged over 11 should not eat more than seven sugar cubes a day.
Where are children getting high levels of sugar intake from?
Children get most of the daily sugar intake from:
Fizzy drinks and juice drinks
Buns, cakes, pastries, biscuits
Breakfast cereals, yoghurts
Sweets, chocolate, ice cream
How can you swap sugary foods and drinks for healthier alternatives?
Health bosses say it is possible to significantly reduce your children's sugar intake by doing a simple swap of common foods and drinks consumed a certain times of day.
Swapping sugary drinks like cola for alternatives like water, low-fat milk and juice drinks with no added sugar
Exchanging sugary cereals for plain cereals or plain porridge
Eating plain yoghurt with a banana instead of sugary yoghurts
Changing chocolate biscuits for nutty apple and celery rice cakes
Replacing a chilled desert with sugar-free jelly
What shopping tips can help you buy healthier snacks?
Skip the sweetie aisle
Bigger isn't better: Buying drinks and foods in a larger size or volume might be better value, but you're just consuming more sugar!
Look for reduced sugar and no-added sugar versions of your regular brands
Try a healthier choice of yoghurt, ketchup or baked beans a try instead of the sugary option
How can too much sugar affects children health?
Sugar leads to the build up of harmful fat on the inside that we can't see
It builds around vital organs and can cause weight gain in addition to heart disease, type 2 diabetes and some cancers
Too much sugar can also cause tooth decay
More than one in five children start primary school overweight or obese, rising to more than a third by the time they start secondary school.
Measures are being introduced to try and tackle childhood obesity such as banning junk food advertising.
Dr Alison Tedstone, chief nutritionist at Public Health England, said: "It's crucial for children to have a healthy breakfast, but we know the mornings in a busy household can be fraught.
"That's why we've developed our Be Food Smart App, taking some of the pressure off parents and helping them to choose healthier food and drink options for their children."