At present, in guidelines created by Labour, families earning under 60% of the median income are considered to be in poverty, but Duncan Smith said that examples of drug addiction and homelessness will now be included.
The previous government introduced the Child Poverty Act, binding all governments to try and eradicate child poverty in the UK by 2020. However, figures suggest that Labour missed their targets before leaving power in 2010, leading to accusations of abandoning families to poverty.
Speaking to BBC Radio 4’s Today programme, Duncan Smith said, "It's not that redistributing income [isn't] right... we have to do some of that, but we need to make sure that what we're doing has a change to someone's life. Not just leaving them as they are with more money, but actually getting them to the state... where they take control of their lives.
"That's fair to them and then that becomes fair to taxpayers who accept that what they're paying their taxes for is reasonable because they're seeing something changing."
He is expected to add in a speech later today, "Unless we find a way of properly measuring changes to children's life chances, rather than the present measurement of income alone, we risk repeating the failures of the past.”
However, Alison Garnham from the Child Poverty Action Group also told the BBC that low income does have the biggest impact: "Poor children on a low income are behind in education, they are likely to suffer more lifelong limiting illnesses, die younger, and have poor self-esteem.”
A new consultation on how to handle child poverty will begin in the autumn.