Writing in the Proceedings of the National Academy of Sciences, researchers said two blood samples taken 12 hours apart showing the concentration of hormones and amino acids can reveal an individual's personal body time, the Los Angeles Times reported Monday.
That body time, knows as the circadian rhythm, regulates many cycles in the human body such as sleep, digestion and metabolic processes and can be thrown off by shift work, jet lag or an irregular lifestyle.
The 12-hour method of blood testing can pinpoint personal body time to within 3 hours, the researchers said.
It examines the level of 50 different metabolites and compares them to a timetable, lead author Takeya Kasukawa, a genomicist with the RIKEN Center for Developmental Biology in Kobe, Japan, said.
The findings could benefit those who are dieting, since eating at the wrong point of a circadian cycle can lead to putting on weight.
They could also be important for people taking medication with severe side effects, such as certain anti-cancer drugs that are most effective when taken at specific body times but can be toxic at other times.