As part of the new study, around 94 products such as fruit leathers, flakes, gums, chews, and coated dried fruit on sale by various UK retailers were tested.
Of all the tested products, 80 of them including The Fruit Factory Sports Mix-Ups, Tesco Yogurt Coated Strawberry Fruit Bites, Fruit Bowl Fruit Flakes Raspberry Rush, Whitworths Sunny Raising Coated Custard Raisins, Organix Goodies Organic Fruit Gummies strawberry and apple were found to contain more sugar than Haribo Starmix confectionary.
The group said that some of the products even carry labels claiming that they can contribute to one of the recommended five portions of fruits and vegetables a day.
Action on Sugar nutritionist Kawther Hashem said: "It's high time food manufacturers stop adding unnecessary sugars and calories to already sweet products. Check the label and if in doubt - eat fresh fruit. Ready sliced fruit in snack pots are better than processed fruit snacks.
"To eat the same number of grams of sugars in a processed fruit snack (18g) your child will have to eat about 240g of strawberries - that's equivalent to a whole punnet!"
Around 99% of the tested products will now need to carry a red color coded warning on the label for high sugars.
Figures released also show that a third of girls and boys aged 11-15 years in the country are considered overweight or obese.
