Nearly one in five children in the UK live in constant poverty, research suggests.
A study found 19 per cent of youngsters grow up in households with an income that is 60 per cent less than the national average.
Children who experience poverty throughout their youth are three times more likely to develop mental-health problems, the research adds.
They are also twice as at risk of suffering from a lingering illness and one-and-half times more likely to be obese.
Nearly one in five children in the UK live in constant poverty, research suggests (stock)
The study was carried out by the University of Liverpool and led by Dr Eric Lai, a postdoctoral research fellow in the department of public health and policy.
Poverty affected 30 per cent of children in the UK between 2016 and 2017 - a 27 per cent rise from 2010-to-2011, the researchers wrote in the journal BMJ.
And these numbers are expected to continue to increase over the next five years.
Growing up in poor surroundings has been shown to affect a child's cognitive, social and behavioural development.
It has also been linked to low self-esteem among both youngsters and their mothers.
These poor health outcomes can continue into later life, with education and employment also being affected, the researchers wrote.
However, few studies have looked at how growing up in and out of poverty affects a youngster's health.
The researchers therefore analysed data on 10,652 children from the UK Millennium Cohort Study, which follows 19,000 people who were born between 2000 and 2002.
Poverty, defined as having a household income of less than 60 per cent of the average, was measured when the children were nine months old, and again at three, five, seven, 11 and 14 years.
The youngsters' physical health was determined by looking at their BMI.
And their mental wellbeing was assessed via a questionnaire that asked about any hyperactivity, emotional problems or issues with peers.
Poverty raises a person's risk of poor health.
One in five people in the UK live in poverty, which is often defined as having a household income of 60 per cent