The new study, led by Imperial College London, shows that obesity has a 'metabolic signature' detectable in urine samples, pointing to processes that could be targeted to mitigate its effects on health.
Urine contains a variety of chemicals known as metabolites, from a vast range of biochemical processes in the body.
Technologies that analyse the metabolic makeup of a sample can therefore offer huge amounts of information that reflects both a person's genetic makeup and lifestyle factors.
They found 29 different metabolic products whose levels correlated with the person's body mass index, and how they fit together in a complex network that links many different parts of the body.
Some of these metabolites are produced by bacteria that live in the gut, highlighting the potentially important role these organisms play in obesity.
Altered patterns of energy-related metabolites produced in the muscles were also identified as being linked to obesity.
"Obesity has become a huge problem all over the world, threatening to overwhelm health services and drive life expectancy gains into reverse," said Professor Jeremy Nicholson, Director of the MRC-NIHR National Phenome Centre at Imperial College London and a senior author of the study.
"These findings provide possible starting points for new approaches to preventing and treating obesity and its associated diseases," Nicholson said.
"Our results point to patterns of metabolic markers in the urine associated with obesity. It may be possible to identify non-obese people who have such patterns in their urine profile," said Professor Paul Elliott, Head of the Department of Epidemiology and Biostatistics at Imperial.
"These people could be at risk of developing obesity and metabolic diseases, and might benefit from personalised preventative interventions," Elliott said.