Within-Family Obesity Associations

A mother walking with her daughters on sidewalk.

Among same-gender siblings in a two-child household, obesity status was strongly correlated, a new study finds. This association indicates that sibling influence on obesity status may differ from a parent influence.


The Issue:

The association of obesity among parents and their offspring has been widely researched. Here, the authors examine the associations of obesity among siblings as well as among parents.

Key Findings

  • The obesity status of a younger child’s elder sibling is more strongly associated with a child’s obesity than is the parent’s obesity status.

  • Within-family obesity was more strongly patterned among siblings of the same gender than between different genders.


The influence that a sibling may have on a child’s obesity status is an important consideration for future study on obesity prevention and intervention.

About the Study:

Participants completed the Family Health Habits Survey via the Internet during 2011. A total of 1,948 adults reported having one or two children living at home under the age of 18. Sociodemographic information, parent and child height and weight, physical activity level, and food environment information were analyzed in 2012–2013.