The city's poorest spend more of their income on food than a decade ago as inflation continues to push prices higher.
Groceries account for more than half of their monthly household expenditure, a study found.
For the poorest 5 per cent of three-member households in the city, 51.5 per cent of their average HK$5,181 a month spending went towards food in 2009-10, up 8.8 percentage points compared with 10 years earlier.
That means each member in those families spent about HK$29.60 on meals every day, compared with HK$26.60 in 1999-2000.
The Council of Social Service yesterday released its analysis based on data from the Census and Statistics Department's household-expenditure surveys of 1999-2000 and 2009-10.
"There has been serious inflation in food prices, but the rise in spending could also be, in part, because families can spend more on food as public-housing rent waivers help lessen the housing burden," said Chua Hoi-wai, the council's business director of policy research and advocacy.
In 2009-10, 16.7 per cent of the average monthly spending for a three-member household went to housing, down from 22.6 per cent of HK$5,609 per month in 1999-2000.
But Chua said that some low-income households still needed to squeeze their food expenditures in order to meet other living costs.
Christine Fang Meng-sang, the council's chief executive, proposed that the government set up more community hot-meal canteens to serve the elderly and poorer households, and that it lengthen the period over which the poor could receive food aid.
She also said the Housing Authority should ensure the average waiting time for individual applicants 40 or older seeking public-rental flats be kept to three years, even if they were not elderly.