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Member Research & Reports

Member Research & Reports

Michigan Study: Birth of a Sibling Potentially Linked to Healthier BMI’s for Children by First Grade

A new study at the University of Michigan, believed to be the first of its kind, has discovered an association between whether or not a child has a younger sibling, and that child’s BMI. Specifically, it appears that children who do not have siblings are almost three times more likely to be obese by the time they reach first grade than children that do have siblings.

Because childhood obesity is a matter of great concern in the U.S., the implications of this study could be significant in the quest to determine the factors that contribute to obesity and develop strategies to change them. However, more research is necessary to tease out the mechanisms for how this association between BMI and the birth of a sibling occurs. Current speculations about this from the study’s authors include the possibility that family eating behaviors may change when a sibling is born, or that children may have less sedentary and screen time when there is a new child in the home with whom to play.

The findings of this study, in which 697 U.S. children participated, will appear in the April issue of Pediatrics, and will hopefully set the stage for a new body of research that aims to explain this connection between siblings and obesity. A better understanding could help families across the country create household patterns that encourage metabolic health.

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