Children and young people in the city are consuming more than two-and-a-half times as much sugar as the maximum recommended daily intake - most of which is coming from sugary drinks.
Sheffield Council has launched a campaign at Forge Valley, in Stannington, Yewlands Academy, in Grenoside, and Parkwood Academy, in Shirecliffe, to encourage pupils, teachers and pupils to switch from sugary drinks to water or milk for four weeks.
The Give Up Loving Pop challenge and the dangers of excess sugar will feature in assembles and PSHE lessons.
“Although some pupils understand the principles of a balanced diet, many are unaware of the sugar content of what they eat and drink.
"This can have an ever lasting impact on their health and well-being.
“We are hoping that through the current media drive and our PSHE lessons our pupils become educated enough to make informed decisions about what they are drinking on a regular basis and it will have a positive impact on their lifestyle choices."
Sugary drinks can cause various health issues including tooth decay, obesity, heart disease and type two diabetes.
One can of cola alone contains nine cubes of sugar - two more cubes than the recommended daily maximum of seven cubes for a teenager.
Director of Public Health at Sheffield Council, Greg Fell, said: “Children have far too much sugar in their diet, and much of this comes in the form of sugary drinks.
"Not only is this causing problems for children and young people now in terms of tooth decay and weight gain, but continued over-consumption of sugar can lead to problems in later life.
"Evidence shows that regardless of weight, consumption of sugary drinks can lead to cardiac and metabolic issues in adulthood.
“We are also aware of the effect that sugary drinks, especially in the form of energy and sports drinks can have on behaviour during school and academic performance.
"The GULP campaign will educate our young people about the benefits of switching to water or milk and we hope that the messages will be taken home, to impact on family and friends.”
Councillor Jackie Drayton, cabinet member for children, young people and families at Sheffield Council, encouraged people to look at the ingredients in food and drink.
She said: "We all know that too much sugar is bad for children and young people and can cause health problems now, and in the future.
"I remember as a young mum I didn’t realise just how much sugar there was in various prepared food and drinks.
"So I switched to giving my children plain milk or water, and ever since always look at what ingredients are in food and drink, to find out what’s hidden in them and I’d encourage everyone to do the same.
“I’m so please to see our schools taking part in this campaign to improve the health of the children and young people in the city and would ask all parents and carers to support them.”
All schools, students, teachers and parents can sign up for the GULP challenge at www.giveuplovingpop.org.uk/gulp-challenge