A University of Minnesota project has shown that training and support for low-income parents can help reduce obesity in children who are most at risk, offering hope at a time of rising concern about overweight American youth.

University researchers offered home visits, health classes and phone check-ins to more than 250 low-income parents, then compared the weight levels and health habits of their preschool-aged children with those from families in a control group.

While weight levels did not drop measurably for all the children, the supports did help two key subgroups. Weight levels improved over three years in Hispanic children — who historically have been much more likely to be obese — and among children who were already overweight.

“I think it’s a success,” said Simone French, a childhood nutrition researcher at the U who led the study. “It showed us that the ones who are most receptive to these type of activities, the ones we’re really trying to focus on, did well.”

The U was one of four institutions that received federal funding in 2010 to determine if educational or social support programs could reduce childhood obesity — a significant public health problem in the United States because obese children typically become obese adults who suffer higher rates of diabetes, heart disease and even certain cancers.

At the time, rates of childhood and adult obesity were skyrocketing. Since then, childhood obesity levels have leveled off amid a range of public health efforts. In Minnesota, for example, state grants funded healthy snack and walk-to-school programs. A Robert Wood Johnson Foundation report last month showed that obesity had declined among low-income preschool children in the state from 13.9 percent in 2004 to 12.3 percent in 2014.

Obesity remains a problem, though, especially for minority and low-income children, the data show. The 2016 Minnesota Student Survey showed an obesity rate of 15.2 percent among Latino eighth-graders, compared with 8.5 percent of their white classmates.

“Far too many young people in this country are facing increased chances of diabetes, heart disease, and high blood pressure, all due to a preventable condition,” said Jamie Bussel, senior program officer with the Robert Wood Johnson Foundation. “And black and Latino youth are still more likely than their white peers to face these problems.”

The university study measured success by change in body mass index (BMI), a calculation that takes into account weight and height. While BMI levels should naturally increase for children as they age, the researchers hoped to see less growth in those who received the support services.

Hispanic children in the support group actually had higher average BMI levels than Hispanics in the comparison group at the start of the study. But three years later, their average levels were lower, according to the study results, published in the American Journal of Public Health.

While the study didn’t see that BMI change in children overall, French said it found declines in the children’s caloric intake and screen time.

The Minnesota project, funded by a $7 million federal grant, is the only one of the four so far to find that support could improve body mass results in key demographic groups. French said the researchers at the four sites are examining all of the findings to see what worked in Minnesota.

Results from Stanford University haven’t been published yet, but an initial look suggested that its strategy of home visits directed at overweight teens didn’t pay off. A study at Vanderbilt University mirrored the U of M approach, in that it targeted educational efforts at the parents of preschool children, but French said that program lacked the home visits, which might have contributed to the U’s results.

“Three years is a long time, which is one of the things we learned,” French said. “It’s a long time and parents need flexibility in terms of what they can do, and when.”

Many of the families in the study moved more than once, for example. In the first year, the average parent received eight home visits, participated in five classes, and received three check-in calls. They also received access to activities such as introductory swim classes at the YWCA to expose them to healthy options in their communities.

Activity levels dropped in the second and third years of the program, though.

“They have a lot of challenges compared to families with more income and more stability in their lives,” French said.

Grant funding has been extended so the U can monitor the children to see if the support program in their preschool years keeps paying off in their grade-school years.