OUR CONCEPT of what constitutes acceptable weight is formed in early childhood and is not highly influenced by our social contacts in later life, a study published yesterday suggests.
Researchers at Newcastle University in Britain have concluded that previous studies may have overestimated the effect of social networks on a person’s body mass index (BMI). A social contagion effect in which obesity spreads throughout a social network has been proposed as one explanation for the persistence of high obesity rates.
The theory suggests weight gain of one member in a social group may affect the weight gain of other members of the network.
According to the theory, attitudes about body weight are formed by observing the weight of other members of one’s social group. Individuals whose social group is heavier may view a higher weight as socially acceptable, resulting in the spread of obesity in the social network.
Writing in the journal Obesity, Dr Heather Brown and colleagues investigated the effects of time-constant factors such as genetics and upbringing and changeable factors, such as friends and opportunities for exercise, on the development of social norms regarding weight in children.
They analysed the correlation in BMI data from 236 adolescent siblings living together and 838 adult siblings living apart. Factors such as genetics significantly influenced both groups, but only the adolescent group was influenced by changeable factors.
“The results have shown an important limitation of the social network approach finding no evidence of significant impact of factors that change over time,” the authors said.
“Using social networks to spread healthy behaviours may only be a feasible intervention tool for participants that can engage in face-to-face interactions with social network members helping to anchor social norms that change over time.”