Obesity runs in families - and friends, too

Having overweight family and friends increases the likelihood someone will become overweight, according to a Harvard researcher who examined obesity and social network data from the long-running Framingham Heart Study.

Nicholas Christakis, professor of medical sociology at Harvard Medical School and professor of sociology in the Faculty of Arts and Sciences, said March 6  that the results are not that unusual given that prior research has documented the influence of social networks on the health of people under a variety of conditions.

Perhaps best known is the "widower effect,"or the increased likelihood of death after the death of a spouse. Research published by Christakis last year showed that a serious illness, particularly a psychiatric illness or dementia in a spouse can be just as detrimental to ones health as if the spouse had died.

Additional research has shown other health effects spread through social networks. Treating depression in a parent, for example, can improve the health of their children. Seat belt use by one person can save the life of another by preventing that person from flying around the vehicle in the event of an accident.