The warning was made by health expert Paul Gately, Professor of Exercise and Obesity at Leeds Beckett University, after worrying figures revealed the amount of sugar young people are consuming.
Public Health England (PHE) said that on average, kids have already eaten more sugar than the maximum amount recommended for an 18-year-old by the time they reach their 10th birthday.
Prof Gately said sugar was an important factor in children’s health, but the biggest issue is the overall calorie count of what they eat.
He said: “One of the biggest issues is public health messages tend to sway. The worse thing we can do, I believe, is confuse the population.
“Balance, moderation and calories are key.”
The recommended maximum amount of sugar for 10-year-olds is 20-24 grammes a day.
But PHE’s National Diet and Nutrition Survey found that children are consuming 52.2 grammes a day.
That is equivalent to 13 cubes a day, eight more than the recommended level.
Prof Gately said planning ahead was crucial to kids having a healthy meal, but that was not always easy for families.
He said: “If as a parent you are not planning or organising meals then children will be eating worse food.
“Because it’s easy to grab food as you move, the consequence of that is ill-health and obesity.
“When you are in shift work and dealing with child minders or in a split family, that all impacts on how busy life is.”
“I think the message is, yes sugar is important, but let’s put that in context and appreciate that for hard working parents it’s not easy.”
Dad-of-five Prof Gately also encouraged families to use supermarket shopping apps which help keep count of calories. He added: “There are some great apps out there. There are lots of ways of doing that if parents embrace it. ”
The national Change4Life campaign is encouraging parents to change their shopping habits.
Making different choices of yogurts, drinks and cereals could cut a child’s sugar intake by half, according to PHE