Researchers hope the disease can be prevented in later life by testing people when they are young.
Scientists have discovered indicators of adult type 2 diabetes can be spotted in children as young as eight - about 50 years before it is usually diagnosed.
University of Bristol researchers analysed genetic information known to increase the chances of the disease and metabolism measures in thousands of British children.
They found being more susceptible to type 2 diabetes affected children's levels of high-density lipoprotein (HDL) cholesterol, amino acids and a chronic inflammatory trait measured in the blood.
Some of the earliest indicators of susceptibility were certain HDL lipids.
Scientists hope the metabolic features could be targeted to prevent young people from developing the disease which is often linked to being overweight or inactive, unlike type 1 patients.
It is also linked to having a family history of type 2 diabetes.
Dr Joshua Bell, from the MRC Integrative Epidemiology Unit at the University of Bristol, said: "It's remarkable that we can see signs of adult diabetes in the blood from such a young age - this is about 50 years before it's commonly diagnosed.
"This is not a clinical study; nearly all participants were free of diabetes and most will not go on to develop it.
"This is about liability to disease and how genetics can tell us something about how the disease develops."
The study will be presented as this year's annual meeting of the European Association for the Study of Diabetes in Barcelona, Spain.
More than 4,500 participants born in Bristol in the early 1990s were tracked as part of the research.
Researchers measured 229 metabolic traits on the healthy participants when they were aged eight, 15, 18 and 25 to see how early diabetes susceptibility is visible.
They found HDL cholesterol levels were reduced at eight years old, and inflammatory glycoprotein acetyls and amino acids were elevated by the mid to late teens.
Dr Bell, who co-led the research, added: "If we want to prevent diabetes, we need to know how it starts.
"Genetics can help with that, but our aim here is to learn how diabetes develops, not to predict who will and will not develop it.
"Other methods may help with prediction but won't necessarily tell us where to intervene.
"Knowing what early features of type 2 diabetes look like could help us to intervene much earlier to halt progression to full blown diabetes and its complications."
PUKmedia / Sky News