A Japanese company will soon start advising people what they should eat and how they should exercise based on custom-made analysis of their genes, in what the firm says is a world first service.

Signpost Corp, which will launch the service in April in Japan, will also assess risks of a heart attack and stroke while telling a customer how likely he or she is to suffer kidney and sight problems if hit by diabetes.

"Genes can tell various health risks ... such as if you are prone to be obese or tend to have problems with your blood vessels," Signpost business planning official Nana Ozaki said.

Anyone who wants to have the service would go to a hospital to give five millilitres (0.15 ounces) of blood for analysis of some 60 genes. The customer would also list his or her height, weight and dietary habits.

The results will come in 30 to 45 days through a doctor or other experts, Ozaki said.

The service will cost several tens of thousands of yen (several hundred dollars), although the exact charge will depend on which hospital the customer goes through, she said.

Signpost is a start-up company set up by researchers affiliated with state-run Osaka University.

Signpost has already been offering genetic examination to assess risks for hardening of the arteries or complications from diabetes, attracting several hundred people since its launch in December 2005.