Spanish families have begun to reduce the amount they spend on food due to money problems, according to the Ministry of Agriculture.
Consumer groups say tax increases, lower wages and rising unemployment are at the root of the problem and are giving increasing cause for alarm among charities, NGOs and others involved in helping the poor.
Consumer associations say the first sign of stress in the shopping basket is switching from so-called traditional, named brands to cheaper alternatives.
Latest data from the Ministry of Agriculture reveals that many people have also stopped buying that traditional Spanish staple Olive Oil in favour of cheaper alternatives, such as sunflower and other oils.
According to Vicente Stinga, spokesman the General Association of Consumers, it is a sign of just how desperate things have become, with the shopping basket the last frontier to be crossed in the battle to make ends meet.
Stinga warned things will only get worse as more people run out of benefits with no prospect of finding employment in a job market getting worse by the day.