Urine test spells end to diet lies

The process measures the biological markers for a variety of foods including red meat, chicken, fish and fruit and vegetables and how much fat, sugar, fibre and protein.

Created by scientists at Imperial College London in collaboration with the universities of Newcastle and Aberystwyth, the work was published in the journal Lancet Diabetes and Endocrinology.

Co-author Professor Gary Frost of Imperial College explained: "A major weakness in all nutrition and diet studies is that we have no true measure of what people eat.

"This test could be the first independent indicator of the quality of a person's diet - and what they are really eating."

Professor Gary Frost, Imperial College

"We rely solely on people keeping logs of their daily diets - but studies suggest around 60 per cent of people misreport what they eat to some extent.

"This test could be the first independent indicator of the quality of a person's diet - and what they are really eating."

The experiment, funded by funded by the Medical Research Council and the National Institute for Health Research was conducted at the MRC-NIHR National Phenome Centre. Researchers gave 19 volunteers four different diets, ranging from very healthy to very unhealthy.

These were based on World Health Organisation dietary guidelines for the best diets to prevent conditions such as obesity, diabetes and heart disease.

After following their diets for three days the volunteers provided urine samples three times a day and assessed these for metabolites, the compounds produced when particular foods are broken down in the body.

A urine metabolite 'healthy diet' profile was produced. The scientists then tested for accuracy on a sample of 291 people in the UK and Denmark, accurately predicting their diets.

Professor Elaine Holmes, co-author from the Department of Surgery and Cancer at Imperial added: "We are hoping to make this test available to the public within the next two years."