Children should be eating a third of their weekly fibre and protein in school meals, new guidelines recommend.
By Alison Smith
BBC News education
But surveys suggest half of children bring in food from home. Can the ever-popular packed lunch be regulated - and how healthy is it?
Ashmount Primary says nutrition is a high priority
At Ashmount Primary School in north London sandwiches were very much on the packed lunch menu - as well as fresh fruit.
Lucy, eight, tucked into her favourite sandwich variety - hummus and cucumber.
"Sometimes my Dad says I shouldn't eat so much of it," she said.
"But it's my favourite - and I usually get it if I ask. I seem to remember having strawberry jam once as well -
but I usually have this.
"I always have fresh fruit as well though. I had a peach and
Sylvie, 11, said her parents discouraged her from eating sugary snacks - so she had a sandwich with ham, fresh fruit including an apple, and drank orange juice.
"I am also allowed a brunch bar, but not one that's high in sugar. And sometimes I will have pasta or couscous instead of sandwiches, so I get a variety."
Her friend Jess nodded. "I'm only allowed crisps when we go on a school trip."
Seven-year-old Dan said he brought in chocolate for his packed lunch - but only once a week.
"I had a sandwich today and my favourite thing - Monster Munch crisps. I have fruit such as an orange as well though, or sometimes I have a sausage roll."
All said their parents were concerned and aware about the food they aet while at school.
And they had friends who were vegetarian, who preferred to bring their own food too.
Fizzy drinks ban
Deputy head teacher Ranna Pandya said packed lunches were and always had been popular.
"Some don't like what's on offer for school meals.
"Some find it's not the type of food they're used to eating at home. And there are those children who are just fussy about food.
Ranna Pandya says the staff are very aware of what pupils are eating
"We offer salads and vegetables but the children don't always go for them. Pizza and chips are popular.
"It's not the fault of the school or the children - there needs to be more money but also everyone needs to do more to educate about food and nutrition.
"I personally feel very strongly that children should have a good lunch.
"On occasions you know some children have not had a good breakfast, so lunch is important. The wrong food can affect their behaviour and emotional state."
Ashmount Primary has banned all fizzy drinks from the school.
"I think it's right not to allow them," she added. "Water is freely available instead."