Children should be given no more than two 100 calorie snacks per day in a bid to help cut childhood obesity, campaigners have warned.
The latest guidelines from Public Health England (PHE) come as they warn that unhealthy snacks eaten by children contribute to half the sugar consumed by them each day.
PHE said on average children are eating at least three unhealthy snacks or sugary drinks a day, and called for parents to buy snacks of no more than 100 calories at a time as part of its new Change4Life campaign.
These unhealthy snacks and drinks amount to the equivalent of around seven sugar cubes a day, PHE said, adding that the recommended daily maximum is no more than five cubes of sugar for four to six-year-olds and no more than six cubes for seven to 10-year-olds per day.
Each year children are consuming almost 400 biscuits, more than 120 cakes, buns and pastries, around 100 portions of sweets and nearly 70 of both chocolate bars and ice creams - washed down with more than 150 juice drink pouches and cans of fizzy drink.
Healthier snacks, the Change4Life campaign says, would help tackle an obesity epidemic that sees a third of children leave primary school overweight or obese.
PHE says its new advice about limiting snacks does not apply to fruit and vegetables, as children should be encouraged to eat a variety of these in order to achieve their recommended five portions of fruit and vegetables per day.
The campaign will offer parents special offers on a range of healthier snacks, including fruit and vegetables at selected supermarkets.
Rather than snacking on junk food, the campaign suggests that parents give their children snacks such as fruit, chopped vegetables with hummus, plain rice cakes, crackers, malt loaf, crumpets and Scotch pancakes.
"The true extent of children's snacking habits is greater than the odd biscuit or chocolate bar. Children are having unhealthy snacks throughout the day and parents have told us they're concerned,” said Dr Alison Tedstone, chief nutritionist at PHE.
"You see children buying chips coming out of school and buying a bag of chips on their way home from school, and that's part of the reason why we have an obesity epidemic in this country.
"To make it easier for busy families, we've developed a simple rule of thumb to help them move towards healthier snacking - look for 100 calories snacks, two a day max."
Justine Roberts, chief executive and founder of Mumsnet, said: "The volume of sugar kids are getting from snacks and sugary drinks alone is pretty mind blowing, and it can often be difficult to distinguish which snacks are healthy and which aren't.
"This rule of thumb from Change4Life will help parents make healthier choices, which can only be a good thing."
PHE is working with the food industry to cut 20% of sugar from the products children consume most by 2020.
How many calories are in popular snacks?
An average ice cream - 175 calories
Packet of crisps - 190 calories
A chocolate bar - 200 calories
A pastry - 270 calories
What do 100 calorie snacks look like?
A matchbox-sized block of cheese
Two small, non-chocolatey biscuits, for example, two gingernuts or one-and-a-half custard creams
One Twix finger
Two Jaffa cakes
Three squares of Dairy Milk
A tablespoon of dried fruit
Eight dried apricots
Seven Fruit Pastilles
Two crackers/rye breads with a tablespoon of low-fat, soft cheese