MIAMI (AFP) - One in three Americans does not get enough sleep on a regular basis, raising their risk of obesity, diabetes, high blood pressure, heart disease and stroke, US health authorities said on Thursday.

Healthy sleep is defined as at least seven hours per day for adults aged 18-60, according to the report by the US Centres for Disease Control and Prevention.

The findings are part of the "first study to document estimates of self-reported healthy sleep duration for all 50 states and the District of Columbia," said the CDC in its Morbidity and Mortality Weekly Report.

Sleep patterns varied nationwide by location and ethnicity, as well as employment and marital status, said the study which was based on randomly dialed telephone surveys.

Whites were most likely to get enough sleep - with 67 per cent of non-Hispanic white reporting "healthy sleep duration," compared to just 54 per cent of African-Americans.

Sixty-six per cent of Hispanics and 63 per cent of Asians reported getting enough sleep per night.

The lowest proportion of adults who slept adequately was centred in the southeastern United States, an area that also has the highest prevalence of obesity and other chronic conditions.

Being out of work or being sick also made it harder to sleep for more than half of those surveyed.

People with a college degree or higher were most likely to report healthy sleep patterns - at 72 per cent.

Married people were more likely (67 per cent) than never-married (62 per cent) or divorced, widowed or separated (56) people to get at least seven hours of sleep a night.

"As a nation, we are not getting enough sleep," said Wayne Giles, director of the CDC's Division of Population Health.

"Lifestyle changes such as going to bed at the same time each night; rising at the same time each morning; and turning off or removing televisions, computers, mobile devices from the bedroom, can help people get the healthy sleep they need."