Professor John Struthers, from the Association of Christian Economists, was speaking after Consumer Price Index (CPI) inflation jumped from 0.6% to 1% in August.
The jump is more than economists expected and represents a two-year high for CPI inflation, which is based on a basket of goods most households in the UK are likely to buy regularly.
An increase in inflation is mixed news for consumers. The cost of goods of increases, but the cost of debts decreases.
The fall in sterling's value by 16% since the UK voted to leave the EU is the main reason inflation's increased, as products sold in other currencies become more expensive for Britain to buy and import.
The fall in the pound's value means British goods are more attractive to buy, however.
Asked on Premier's News Hour whether he thought churches could see more people needing help, Professor John said: "There's a very real possibility that this may happen.
"There is already quite a serious problem in the UK with people who're really struggling to feed their families. We've seen an increase in foodbanks.
"We're a net importer of food into this country, and clothing. These are items that the less well-off spend a disproportionate amount of their salary on, and I think we should be concerned about that."
Listen to Premier's Alex Williams speaking to Professor John Struthers on the News Hour:
