How thick do you spread your butter?
Do you remember exactly what you ate yesterday? How thick do you spread your butter? I ask because 500,000 adults in Britain are being surveyed on their eating habits. All are participants in UK Biobank, a huge medical research programme funded by the Wellcome Trust, the Medical Research Council and the government.
You won't easily forget if are one of the 500,000. On enrolment all of us underwent a battery of medical checks. We also donated genetic material which will be stored for several decades. Scientists hope the project will lead to improved diagnosis and treatment for a host of conditions, from dementia to heart disease and cancer.
Which brings me to the food survey. Like other participants I was sent a comprehensive online questionnaire designed to detail every morsel I consumed yesterday. There was a long list of vegetables, from carrots to aubergines, next to which I had to tick the box marked "none". Other items included alcohol - one medium glass, and butter on bread - spread not thinly nor thickly, but just right to my taste. I imagine a researcher raising an eyebrow after seeing that I had at least three portions of "hard cheese". But then again one portion is listed as being "the size of a small matchbox" - hardly a mouthful!
There were also a couple of questions on physical activity. Sadly, it was not a day that I cycled 50 miles, but I did do some light exercise, thank goodness - namely running for a train and lugging heavy camera equipment around a hospital.
So what is the point of it all? The researchers at UK Biobank already know about my weight, eyesight, lung function, hearing, grip strength, bone density, not to mention sexual history and lifestyle. Then there are the samples of blood, urine and saliva in storage in a massive freezer near Stockport.
"Asking additional questions about diet and physical activity over the internet is a very simple way to add considerable detail to the resource," said Dr Tim Sprosen, UK Biobank Chief Scientist.
"This makes it more valuable to scientists when finding out how lifestyles influence our chances of developing a wide range of ailments, or working on better prevention."
So over the next 30 years as the 500,000 participants age, the researchers will have a huge amount of data to sift through and find out many more genetic and lifestyle factors which influence health.
What about how thick I spread my butter - is that really useful, or prying on a man's breakfast habits just a bit too much? Dr Sprosen said: "The type and thickness of a spread on bread can be important in determining fat consumption, especially if the individual eats lots of sandwiches. What we put on our bread, or jacket potato, can be as important as the meal itself in terms of nutrition, and often this is overlooked." Oh, ok then.
Don't worry if you are a UK Biobank volunteer and have not received your food survey yet - they are being sent out over the next couple of months. Later this year the team plan to ask participants if they will wear a watch-sized accelerometer or motion sensor for a week. As a gadget lover, I can't wait. And that surely will be the week that I exercise a lot and spread my butter more thinly.