When Abby Sanders and her husband, Matthew, were expecting their first baby in 2012, they went to birthing classes and watched child-care videos. Then little Carter arrived.

"We were clueless. … I'm a teacher, but I don't know what I'm doing with babies," recalled Sanders of Lebanon County.

The first-time mom worried that Carter wasn't nursing well.

"I read everything, but it was totally different," she said. "Are we doing this right? The nursing, the bathing, the little things you don't think about."

But Jennifer Stokes, a nurse at Hershey Medical Center, put Sanders at ease. As part of a Pennsylvania State University research study, Stokes came to the Sanders' home several times during Carter's first year to weigh him. She also taught the new parents how to recognize when their son had enough to eat, usually turning his mouth away or falling asleep while nursing.

Sanders was one of 279 first-time moms who volunteered to participate in the study, which examined strategies to soothe fussy infants as a way to prevent obesity.

The women in the study, who all gave birth at Hershey Medical Center, were divided into two groups. Nurses came to the homes of those in the first group to show them how to help their babies "self soothe" when they were crying or irritable but weren't hungry.  The second, control group, were visited by nurses who talked about safety issues but didn't give the mothers specific advice on how to calm their fussy babies without feeding them. The nurses visited the families four times during the babies' first year of life and then followed up yearly until the babies turned 3 years.

Results of the 2012-17 study – published this summer in the Journal of the American Medical Association – show that when the 3-year-olds were weighed, those in the intervention group had lower body mass indexes (BMIs) on average and only 11.2 percent were overweight and 2.6 percent obese, while 19.8 percent of the children in the control group were overweight and 7.8 percent obese.

The study was funded in part by a grant from the National Institutes of Health.

"There's evidence that a lot of our behaviors, including ones related to eating and sleeping, are 'programmed' at a very young age," said Ian Paul, a professor of pediatrics at Penn State College of Medicine and a lead investigator for the study.  "Some of our research is based on the idea that food should be used for hunger, not for other purposes such as to soothe or reward a child. Babies that are soothed with food early on may be more likely to use food to soothe their distress later on in life." And that can lead to obesity with the complications of diabetes, heart disease, and hypertension.

Nurse Amy Shelly came to the home of Aimee Bergner of Palmyra, Pa., to show her and her husband, Tim, how to calm their son, Oliver, when he was an infant.

"It was really, really helpful," Bergner said. "It was a guide you could follow." Oliver is now 6, and Bergner has used the skills she learned through the study to care for her two younger children — Charlotte, 4, and Lenore, 7 months.

Leann L. Birch, professor of foods and nutrition and director of the Obesity Initiative at the University of Georgia, who co-led the study, said that many parents are concerned that their children aren't getting enough to eat when they cry, so a first response is often to feed them.

"Babies cry for many reasons," she stated in an announcement about the study results. They could be cold or hot, tired, bored, or gassy. The study showed that parents could be taught how to use "appropriate infant soothing strategies" including feeding as well as swaddling, a pacifier, and calming sounds or music.

"Let them settle down on their own," she said, but if they are still fussy, they may be hungry and definitely should be fed.

Bergner said the parents in the intervention group were trained to use the "5S's"  — sucking, swaddling, swaying (or swinging), side holding, and shushing  —  to soothe babies. The 5S's are based on a program developed by renowned pediatrician Harvey Karp, author of  Happiest Baby on the Block.

She demonstrated that holding a baby in a side hold, like a football, helps put the infant to sleep.  And allowing a baby to suck on fingers also taught the infant to self-soothe, even without a pacifier. Shushing or having soft noise or music playing in the background also helped.

Patricia Carper of Middletown, a nurse involved in the study, said that many of the first-time moms "were thrilled to get the information." Even their friends noticed that the babies trained to self-soothe were much better sleepers, allowing their parents to get more shut-eye as well.

Swaddling, or wrapping  newborns fairly tightly in a swaddling blanket, makes them feel comforted and secure, like they are back in the womb, and is a good thing to do, Carper said, until the baby starts learning to turn over.  Then the swaddling must end because babies need their arms free to maneuver their bodies.

Sanders and Bergner both appreciated learning how to start their babies on solid foods — introducing vegetables one at a time before introducing sweeter fruits, so that the children learn to like veggies and won't become picky eaters.

"It's hard to go back to green beans after you've had peaches," Bergner said.

Now Oliver and Charlotte "will eat almost everything," Bergner said.  She recently started Lenore on solid foods and used the same approach.

Another helpful hint is to order an adult meal and split it between two young children at a restaurant rather than ordering children's meals, which are often higher in fat and sodium.

Carper, a mother of two herself, said she also learned from the experience. "I wish I had all this knowledge when my children were infants," she said.

Though the study ended in 2017, Penn State has received additional NIH grants to continue following the children until age 9 and to conduct a sibling study of second-born children in the same families until age 3, said Jessica Beiler, project manager.

Sanders, whose son, Carter, was part of the original study, has enrolled her second child, Callie, 2, in the sibling study.

"I Iove working on the project," Stokes said. "We've had very few dropouts. I think the parents are committed.  … We have good relationships with them."

The follow up studies will help researchers learn how important a role developing good eating habits in infants and young children is to their long-term development. Birch, the study co-leader, hopes that further research can include families from various cultural and economic backgrounds;  most of the mothers in the Central Pennsylvania group are highly educated and their families are prospering.

"Very early growth rates are predictive of later obesity, cardiovascular disease, and hypertension," Birch said. "There has been so much concern about obesity.  People have turned their attention to prevention."

The studies have been supported by the NIH's National Institute of Diabetes and Digestive and Kidney Disease, the Children's Miracle Network at Penn State Children's Hospital, the United States Department of Agriculture, the Penn State Clinical and Translational Research Institute, and the NIH's National Center for Advancing Translational Science.