Is obesity contagious?

London: Is obesity contagious? Well, so think scientists who claim that people with a higher number of fat friends or relatives are likely to become obese themselves.

Researchers from Arizona State University`s School of Human Evolution and Social Change in the US found a number of ways in which fat people can influence their friends` girth.

The influence, according to the researchers, can be subliminal- where having overweight pals can make people see their weight as "normal" and eat accordingly until they`re the same size.

It can also be more direct, with obese people putting pressure on their slimmer friends to eat more and exercise less until they "achieve the same body size", the Daily Mail reported.

And even being around larger pals can put you at risk of gaining weight yourself, as socialising with them is likely to revolve more around eating or watching TV and less about engaging in physical activity, the researchers said.

For their study, the researchers interviewed 101 women from Phoenix Arizona, alongside 812 of their closest friends and relatives.

By looking at the Body Mass Index [BMI] of the women and their friends and relatives, they discovered that the fatter a woman`s social circle, the more likely she was to be obese herself.

This was because "we learn about acceptable body size from family and friends" with friendships based on eating and engaging in little physical activity more likely to end in obesity, the researchers said.

Despite the findings, published in a paper titled`Shared Norms And Their Explanation For The Social Clustering of Obesity`, the researchers found that most women viewed being fat as a source of shame.

Asked whether they would rather be fat or have a range of socially stigmatised conditions — including alcoholism and herpes — a quarter of women said they would rather suffer from severe depression than be fat, while 14.5 per cent said they would rather be totally blind than obese.

Lead author Daniel Hruschka said: "Interventions targeted at changing ideas about appropriate body mass indexes or body sizes may be less useful than those working directly with behaviours, for example, by changing eating habits or transforming opportunities for and constraints on dietary intake.

"When you see that something like obesity spreads among close friends and family members, this raises important questions about how it`s spreading.