The government is being urged to consider rent control measures after a family services report found they would benefit the poorest members of society.
Commenting on a Christian Family Service Centre report that found poor families in the Kwun Tong area spent about half of their monthly household budget on food, chief executive Kwok Lit-tun said rent control could ease their burden.
High rents in private housing forced people to cut spending on food, the report found.
"No one thought food banks and food support would work in Hong Kong because it was a prosperous place," said Kwok. "But today even the government acknowledges the need for food support. This is an indication that poverty is serious."
However, Kwok said housing remained the most worrisome issue as rent could eat into a family's budget for food, children's activities and other expenses.
The report also indicated that families living in private housing - all in the study lived in spaces of between 80 and 120 square feet - paid around six times more rent per square foot than those living in public housing.
"Rent control may decrease supply [in the private housing market], but it would stabilise rent and benefit the poor in the long run," said Kwok.
"The government said it would conduct research on rent control. It would be irresponsible not to consider [rent control] especially when there aren't any better ideas."
About 850 families in Kwun Tong with three or more people living below the poverty line and at least one full-time working member were interviewed last December about their monthly spending.
Some 667 of the families lived in public housing and 184 in private quarters.
None of the families interviewed were on Comprehensive Social Security Allowance - Hong Kong's welfare dole.
The study found that, for those in public housing, 77 per cent of monthly spending was on food and housing - 53 per cent on food and 24 per cent on rent.
For those in private housing, 58 per cent of monthly spending was on food, 36 per cent on rent.
"Rent directly affects spending on food for those in private housing," said Joyce Ho Mei-yee from Christian Family Service Centre.
Spending on children's education took up around 5 per cent of monthly spending.
Apart from rent control, Kwok said comprehensive food support and support for children in schools would help families.
Kwun Tong was singled out as one of Hong Kong's poorest districts last year. According to the government's poverty report based on 2012 statistics released last September, 157,400 people live below the poverty line.
The poverty line is drawn at HK$11,500 for three-person households and HK$14,300 for four-person households.