Figures show that purchases of fresh produce by UK households peaked in 2006 and 2007 but were 10 per cent lower in 2011.
For the poorest 10 per cent of households, the drop was 15 per cent. These households now average 3.4 portions of fruit or vegetables per person per day - well below the Government-recommended figure of five - and purchase less than half the volume of fruit than the top 10 per cent.
Under-40s buy significantly less fruit and vegetables than those over 60, the report also revealed.
Combining these trends, under-30s in the lowest income category consume fewer than three portions of fruit and vegetables a day. The north-east of England remains the region with the lowest fruit consumption.
But thanks to food price inflation, consumers spent 8.1 per cent more on fresh and processed vegetables between 2008 and 2011, and 6.9 per cent more on fresh and processed fruit.
Potatoes were 25 per cent more expensive in 2011 than in 2007, other vegetables 21 per cent and fresh fruit 19 per cent more expensive - all well above the overall Consumer Price Index rise of 14 per cent over the period.
In contrast to other fresh produce, the fall in poorer households' consumption of potatoes between 2007 and 2011 was minimal.