A new study suggests that although having younger siblings can be annoying in the childhood, but they may be good for your health – You are not likely to get the obesity like other ‘only’ kids has.

Kids who gained a sibling between ages three and four are less often obese than kids who didn’t have a sibling by the time they were in first grade, said the U.S.’ researchers. According the longitudinal study that tracked nearly 700 U.S.’ children, kids with no siblings during their first grade schooling are more often obese compared to kids who have a younger sibling.

The study, published in the journal Pediatrics suggests that the birth of a sibling a few years into a child’s life is linked with a healthier body mass index (BMI) trajectory for that first child.

Dr. Julie Lumeng, a pediatrician at the C.S. Mott Hospital at the University of Michigan and an author on the study, said in a statement:

“The possibility that seems most compelling, is that if you have a younger sibling, you’re more likely to run around. It is possible that when there is a younger sibling in the family, a child might become more active – for example running around more with their toddler sibling. Maybe families are more likely to take the kids to the park when there is a younger sibling, or maybe the child is less likely to be sedentary, watching TV, when there is a younger sibling to engage them in more active pretend play.”
However, the medical researchers pointed that they are not claiming about the direct effect of the birth of a sibling on weight loss of a child in technical terms, but they have emphasized that there is an association, and the survey/study results need to be studied further.

In simple words, a child with a younger sibling always or more likely to engage in some kind of activities, running, fighting and other plays at any given time. A sibling at a smaller age could act as a ready-made playmate for any child. This could also apply to the children with younger kids of any family members living in the same house.

There is another possibility of not becoming obese when having a younger sibling – once a second child arrives in the family, parents, especially mom, wouldn’t focus much on the first child’s feeding practices. Parents will engage more in restrictive feeding practice of the newly arrived child. According to previous similar studies, if a parent restricts a child’s eating, then there is more likely the child gets the obesity.  That means, the child’s ability to learn to listen to their own hunger cues will be less when a parent forced them to eat, which also promote an unhealthy eating habits.

Keith Ayoob, a nutrition expert and associate clinical professor in pediatrics at the Albert Einstein College of Medicine, said family dynamics may play an important role in determining whether a child develops sound eating habits and a healthy BMI.

“There’s a tendency for parents to constantly feed, whether the child is hungry or not,” he said. “Children can be silenced with food — and that really ends up leading to a dysfunctional relationship with food. It’s a very quick fix.”

While reflecting on his 30-plus years working with children and families, Ayoob noted that parents often lack patience.

“I think technology has convinced parents, and everybody, that solutions come instantly, and with kids they just don’t,” he said.

Parents must practice consistency and discipline, and never reward tantrums, he said. But be sure to make it clear to your little one that it’s the bad behavior, not the child, you don’t like.

Both physicians emphasized that no one is recommending having a second child purely for the sake of affecting the first child’s weight.

Instead, Lumeng encourages parents to consider setting up a play date this weekend, or enjoying a day out in the park, to promote healthy habits.

“This study might be a trigger for people to reflect on their family rhythms and what the family dynamic is,” she said. “If there were a younger sibling in the family, how might the rhythms change in a way that might be protective against obesity?”

Dr. Elsie Taveras, chief of general pediatrics at Massachusetts General Hospital for Children in Boston, called the study findings novel and interesting.

“The study was excellent and really well done,” Taveras said. But without research on the mechanism, which was beyond the scope of the study, it’s too early to give any advice or propose a program to help the older siblings maintain a healthy weight, she said.