The Trussell Trust - which coordinates a UK-wide network of food banks - is urging the public to donate food to combat expected "significant pressures" over the school holidays.
New figures, they say, show the number of food parcels to households with children last year rose by 20% (87,496 food parcels) and they expect a similar rise this year.
Keynsham Food Bank, near Bristol, and another in Saltford, North Somerset, are already experiencing pressure to maintain their stock.
They issue, and distribute to other food banks, school holiday bags for children who receive free school meals or are subject to Pupil Premium.
Over a third of all emergency food parcels distributed by food banks in the Trussell Trust’s network go to children.
The school summer holidays are always a busy time for users: we try to lighten the financial load for those families whose budget is very limited and with the free school meals not being available they are having to find additional food throughout the holiday. If we are to end hunger in the UK, we need to make sure everyone is anchored from being swept into poverty."