The five-day message appears to be reaching more consumers, according to the results of a survey by the Food Standards Agency. Almost half the people asked knew about the recommended minimum level, a significant increase on the same study the previous year.

The encouraging message is one of the findings of the FSA's second annual Consumer Attitudes to Food report, which measures the views of 3,000 people in the UK.

However, consumers appeared unsure about what exactly constitutes a portion of fresh produce. At least 70 per cent of people know that an apple is a single helping, but there is confusion about other produce. Correct answers fell by 50 per cent when respondents were asked about the number of plums or how many tablespoons of vegetables there are in a portion.