School meals in England will have to include at least one portion of vegetables a day - and no more than two portions of fried food each week.
Ministers have announced regulations for school food in state schools, which will apply from January 2015.
The regulations promote drinking water and limit fruit juice servings to 150ml (just over a quarter of a pint).
Deputy Prime Minister Nick Clegg said the rules would "continue to restrict unhealthy foods".
Schools will also have to provide a choice of fruit and vegetables as part of the new rules.
The school food plan, designed to promote healthy eating, will be mandatory for local authority schools, new free schools and schools that convert to academies.