Research carried out by the Local Government Association (LGA) found some fruit juices that are often thought to be a healthy option contain more sugar than cola, while many cans of fizzy drink contain twice the recommended daily sugar limit.
With a third of children now classed as overweight, it said such drinks were fuelling the obesity crisis.
Ocean Spray Cranberry Classic juice was found to have 11g of sugar per 100ml, while pomegranate drink Pomegreat had 12.1g. A can of full-sugar Coca-Cola has 10.6 grams.
It also found a can of Old Jamaica Ginger Beer contained 12 teaspoons of sugar - double the World Health Organisation’s 25g recommended daily sugar limit.
The LGA, which represents more than 370 councils in England and Wales, which are responsible for public health, said it is calling for all manufacturers to follow the lead of those that have led the way on sugar reduction.
It said, for example, Britvic, which makes Robinsons, J2O, Tango and Fruit Shoot, has committed to reduce average calories per serving by 20 per cent within five years.
In addition to a commitment from soft drinks companies to reduce sugar, the LGA wants a slice of existing VAT raised on sugary drinks, sweets, crisps, and takeaway food to be invested in preventative schemes like leisure centres, exercise classes and free swimming.
Izzi Seccombe, chairwoman of the association’s community well-being board, said: “It is wholly unacceptable for one normal-sized can of soft drink to contain 12 teaspoons of sugar - double the recommended daily limit.
“Products like these are fuelling the obesity crisis and helping wean a generation of overweight children.
“Some firms are showing willing when it comes to reducing sugar - but others are simply dragging their heels.
“They need to go further, faster. We are calling on the sector as a whole to to step up and show more corporate responsibility.
“In many cases, people are unaware of exactly how much sugar these fizzy drinks contain.
“Manufacturers must also provide clearer, larger and more prominent labelling which spells out the sugar content.
“It is crucial to tackle obesity at an early age.
“Overweight five-year-olds are four times more likely to be obese than their healthy weight counterparts.”
Under the Government’s voluntary “responsibility deal” with leading manufacturers, which has come under heavy fire from public health campaigners, firms have agreed to make calorie reduction pledges.
The British Soft Drinks Association claims calories in soft drinks have been cut by 3.6 per cent in the last three years, while amounts of sugar have been reduced by 4.2 per cent.
The association’s director general, Gavin Partington, said: “The UK soft drinks industry has done more than any other sector to promote calorie reduction, through reformulation, smaller pack sizes and increased promotion of low and no calorie drinks – up by nearly 50 per cent last year alone.
“It’s worth remembering that more than 60 per cent of soft drinks now contain no added sugar.”