Urine Test Can Determine If Diet Is Healthy

January 13, 2017

Telling fibs about the quality of our diet may be about to get harder. Scientists in the UK say they've developed a simple test to show whether we've eaten a healthy meal or loaded up on junk food.

The secret is in our urine. But a 5-minute test can unlock the biological markers created when different foods are broken down in the body.

The analysis can reveal whether we have eaten red meat or fish and indicate whether we are eating fruit and vegetables. The test is sensitive enough to indicate some specific foods such as oranges, grapes and leafy green vegetables.

It can also tell how much fat, sugar, fiber and protein a person has eaten.

Weight Loss Programs

The test has been developed by a team from Imperial College London (ICL), Newcastle University and Aberystwyth University. The work is still at an early stage, but the scientists behind it say it could have a useful role in monitoring people on weight loss programs and making studies into diet and health more accurate.

The scientists say evidence suggests people are unreliable when asked to record their eating habits. For instance, they tend to downplay the amount of unhealthy food and over-report fruit and vegetable intake. These inaccuracies may be even more widespread among people who are overweight or obese.

Professor Gary Frost, from ICL, who led the study, says in a statement: "A major weakness in all nutrition and diet studies is that we have no true measure of what people eat. We rely solely on people keeping logs of their daily diets – but studies suggest around 60% 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."

Healthy vs Unhealthy Diets

The study, published in the journal Lancet Diabetes and Endocrinology, involved 19 volunteers who ate 4 different diets, ranging from very healthy to very unhealthy.

The unhealthy option included high fat foods with few fruit and vegetables. The volunteers had sugary cereal for breakfast, fried sausages and waffles for lunch and fried beef burgers topped with cheese for their evening meal.

Those in the healthy group were given wholemeal toast and boiled egg for breakfast, steamed salmon with vegetables for lunch and grilled chicken and veg with whole-wheat pasta for supper.

The volunteers stuck to each of their diets for 3 days while scientists collected urine samples.

The samples were analyzed for compounds, called metabolites, produced during the digestion process. The information was then used to draw up profiles to indicate whether or not individuals had followed a healthy, balanced diet with plenty of fruit and vegetables.

The test's accuracy was verified by comparing the results to another study involving diet and urine samples.

One of the scientists, Professor John Mathers from Newcastle University, says in a statement: "For the first time, this research offers an objective way of assessing the overall healthiness of people's diets without all the hassles, biases and errors of recording what they've eaten."

A Future Tool for a Healthier Lifestyle

The researchers now want to refine the technology by testing it on larger groups of people, including individuals in the real world rather than under laboratory conditions.

According to co-author, Dr Isabel Garcia-Perez from ICL, "This will eventually provide a tool for personalized dietary monitoring to help maintain a healthy lifestyle.

"We're not at the stage yet where the test can tell us a person ate 15 chips yesterday and 2 sausages, but it's on the way."

The scientists believe the technology may one day be used alongside weight loss programs. They say it could also help rehabilitate patients who need to follow a healthy diet after, for instance, a heart attack.

Dr Des Walsh, head of population and systems medicine at the Medical Research Council, which part-funded the study, says in a statement: "Though this research is still in its early stages, it's grappling with essential methods in food and diet studies where advances are really needed.

"Measuring what we eat and drink more accurately will widen the benefits of nutrition research, developing better evidence-based interventions to improve individual's health and reduce obesity."


Objective assessment of dietary patterns by use of metabolic phenotyping: a randomized, controlled, crossover trial, I Garcia-Perez et al, Lancet Diabetes and Endocrinology

Imperial College London (ICL)