If you have had an email asking you to undertake the UK Biobank diet questionnaire now, you can log in here, though it is more straightforward to log in from the invitation email.

UK Biobank is asking participants who have provided their email addresses to undertake its online diet questionnaire.

During their assessment, participants gave UK Biobank a summary of their typical diet – but to understand how food intake varies and to maximise the nutritional information available, it is best to have several ‘snapshots’ from each participant.

The online questionnaire has been specially designed and is easy to use, so it only takes about 10-15 minutes to complete (more than 100,000 people have completed it so far).

The questionnaire asks about the food and drink participants consumed during the day before they completed it – even if this is not a typical day for them. Participants are encouraged to complete the questionnaire as soon as they receive their notification, although they are able to complete it later if necessary.

“We know that, for a proportion of people, what they ate yesterday will not be what they usually eat,” said Professor Rory Collins. But it is easier to remember what one ate yesterday and it avoids problems associated with people choosing a ‘typical’ diet that may not in reality be very typical at all.

The diet questionnaire has been sent out every 3-4 months to get multiple snapshots of the food and drink participants consume. Accurate recording by participants, repeated several times like this, allows UK Biobank to gain a fuller picture of their typical diet than would be obtained by either asking about a ‘typical’ diet, or by inference from just one day.

Combining the dietary information with the analyses of specific nutrients in blood, urine and saliva samples will refine the measurement of dietary intake further. This will help scientists to improve their understanding of the link between particular aspects of diet and diseases like particular types of cancer and heart disease.

The development of online systems like this will help UK Biobank gain further information to strengthen the Resource for health research. For instance, UK Biobank is making plans to assess previous occupations in more detail in this way. It may also be able to detect evidence of diseases (such as decline in brain function and depression) which are harder to identify through health records.