Zayn Malik has called on the prime minister to "give all children living in poverty" a free school meal.
In a letter to Rishi Sunak, the ex-One Direction star says he relied on free school lunches as a child in Bradford.
He writes that children are stealing food from canteens "because they are so hungry but can't afford to buy lunch".
He is backing a Food Foundation campaign calling for all children in households on Universal Credit to be eligible for free school meals.
The charity estimates 800,000 children in England live in poverty but do not qualify for free school meals.
Although Malik, now known simply as Zayn, is not an ambassador for the charity, he said he felt compelled to write to the prime minister and to share his own experiences.
He wrote: "These children are suffering from lack of concentration, some even resorting to stealing food from school canteens because they are so hungry but can't afford to buy lunch.
"They are also feeling shame which is directly impacting their physical and mental health." he added
"I know what that shame feels like, I have seen it first-hand, as growing up in Bradford, I relied on free school meals."
Zayn hopes his letter convinces the government to include a free school meal for all children living in poverty as part of the Autumn statement on 17 November.