They say “You are what you eat.” Maybe it should also be, “You are where you live.”

A new study has found that the affluence of your neighborhood is linked to your risk of obesity and diabetes. People living in a high-poverty area were more likely to be obese and more likely to have diabetes than those in a low-poverty census tract.

The researchers characterize the association as “modest but potentially important.”

“The effects we see in the study are comparable to what you see from targeted lifestyle interventions or with providing people with medications to prevent the onset of diabetes,” chief author Jens Ludwig of the University of Chicago told Reuters Health in a telephone interview.

He said it shows that “the environment has important impacts on health.”

The study, outlined in the October 20 New England Journal of Medicine, did not directly prove cause and effect. In addition, it only measured diabetes, height and weight at the end of the study, not at the beginning.

The conclusion comes from about 4,500 mothers living in public housing where at least 40 percent of the residents in the neighborhood had incomes below the federal poverty level.

From 1994 to 1998, under the U.S. government’s Moving to Opportunity program, 1,788 were given housing vouchers that were only good in neighborhoods where the poverty level was less than 10 percent. Another 1,312 were given vouchers that were good anywhere. Both groups also got counseling on moving. The remaining 1,398 received no special vouchers and no counseling.

More than a decade later, the government did a followup study on the women, including measurements of height and weight, and a blood test that gauged blood sugar levels over the previous three months.

Among everyone regarded as obese, with a body-mass index of 30 or higher, the neighborhood made no difference. (BMI is the weight in kilograms divided by the square of the height in meters.)

But among seriously obese women with a BMI of 35 or higher, the voucher for moving into a low-poverty neighborhood seemed to have made a difference; about 31 percent of the people who got the voucher had BMI’s of 35 or higher, compared to about 36 percent who didn’t get a voucher.

And 14 percent of the people who got a voucher to move into a better neighborhood were morbidly obese (with a body-mass index of 40 or higher) compared to 18 percent of those who did not get a voucher.

The blood test results showed that 20 percent of the people who did not get a low-poverty voucher had diabetes, compared to 16 percent in the group that was offered the voucher.