Children will be offered more fruits and vegetables as part of a major shake-up of school dinners in England, ministers have announced.

No deep-fried food will be allowed under the new rules, except for baked chips only.

Fibre and wholegrains will also be increased, and breakfast clubs will have to follow nutrition rules for the first time.

Schools will be monitored to ensure they are meeting the guidelines.

The Association of School and College Leaders (ASCL) welcomed the changes, but said it hoped the new rules would not become “another stick with which to beat head teachers”.

But on plans for enforcement, he added: “None of us would consider ourselves experts in health and nutrition. Don’t create another stick with which to beat head teachers when they are trying to do their very best to provide a healthy, balanced meal for those in our schools.”

Under the new plans, sweet desserts will be reduced from a regular lunch offer to twice a week in secondary schools, and once a week in primary schools. They also must now be served with a portion of fruit.

The Government said Coco Pops would no longer be an option and chocolate spread was “not permitted”.

Servings of processed meats such as ham, sausages and chicken nuggets have been reduced to once a week and must come with a side of vegetables or fruit.

The Department for Education said it hoped the reforms would tackle childhood obesity, improve nutrition and support children’s concentration, learning and wellbeing.

Schools will be required to publish food policies and menus online, with monitoring arrangements set to be developed alongside the Food Standards Agency, it said.

Education Secretary Lucy Powell said they were “once-in-a-generation changes” that would “transform school food for children across the country”.

The new food standards will apply to primary and secondary schools in England, but rules for school dinners vary across the UK.