Their new study included 240 obese people. All of the participants had metabolic syndrome (a combination of risk factors that increase the risk of heart disease, stroke and diabetes). And, all were told by their doctors to make lifestyle changes, including improved eating, the study authors said.
The participants were involved in a clinical trial comparing two dietary interventions: the American Heart Association Dietary Guidelines, or exclusively focusing on increasing their fiber intake. The study volunteers also took part in a 14-session behavioral weight-management program at the University of Massachusetts Medical Center in Worcester, Mass., according to the researchers.
"They were referred by their physicians to make lifestyle changes, including dietary changes. They are highly motivated. Even if they live far away from [our clinic], they travel long distances to learn how to change their lifestyles," study senior author Wenjun Li said in a UMass news release. Li is associate professor of medicine and director of the health statistics and geography lab, division of preventive and behavioral medicine at the University of Massachusetts Medical School.
However, even among these highly motivated patients, those who had a shorter trip to the nearest grocery store with a good selection of healthy foods did better in boosting their consumption of fiber and fruits and vegetables than those who had to travel farther for healthy foods, the researchers found.
Nearly 40 percent of the stores in the study area (Worcester County, Mass.) did not offer a good selection of healthy foods, according to the study authors.
While the investigators found a link between the proximity of stores with a wide selection of healthy foods and dieting success, the study doesn't prove that having a good variety of healthy foods nearby will necessarily lead to weight loss.
However, the researchers did try to account for other factors such as age, race, education and income that might have affected the findings. And, even after considering all of these factors, a lack of nearby healthy food remained an issue, according to the report.
The results suggest that easy access to healthy food is as important as personal determination and assistance from health care providers in helping people improve their diet, according to the study published online recently in the American Journal of Preventive Medicine.
"The striking finding is that in order for a dietary intervention to be effective, the participant needs a supportive neighborhood environment," Li said.
The U.S. National Library of Medicine has more about managing your weight with healthy eating.