Scientists from Harvard and the University of California observed 12,000 volunteers for 32 years as part of a study of cardiovascular disease in the United States. Participants met with cardiologists every two to four years. To maintain contact in case of relocation, the scientists asked them to provide the names of relatives and at least one friend.
Elementary precautions resulted in a sensational discovery. Americans Nicholas Christakis and James Fowler found that when one volunteer began to gain weight, his friends also put on extra kilograms. On average, the chances of friends of a 'fat' person gaining weight were twice as high as those of acquaintances of a 'thin' person. Moreover, how far friends lived from each other had no effect on the ability to suddenly gain weight.
There is nothing surprising in this, psychologists say. The authority of a friend is very high for many people, and their lifestyle is contagious. 'Frequent friendly get-togethers at restaurants or barbecues in nature end in weight gain,' said psychologist Maria Stishova. 'And it's quite difficult to refuse friends to eat for company: there is a chance that the group will reject the black sheep. Moreover, food is a pleasure, and with its help you can express affection and good attitude towards a person.' Those who constantly communicate with overweight people understand that there is essentially nothing terrible about excess weight; a person lives and is fine. And that means going on exhausting diets and pedaling exercise machines is not at all necessary.
Obesity can also be 'caught' from close relatives. The probability of gaining weight for those living under the same roof with an overweight person is 40% higher than for people living in a family of 'underweight' individuals. And genes have absolutely nothing to do with it, American researchers assure. If you do not live in the same house with overweight relatives, your chance of gaining weight is negligible.
It's all about the common diet for all family members, experts believe. In rare households is everyone offered to eat according to a separate menu. 'A family person, as a rule, leads a calmer lifestyle with regular meals at home,' says Alla Pogozheva, head of the cardiovascular pathology department of the Clinic of Therapeutic Nutrition of the Russian Academy of Medical Sciences. 'Naturally, if an overweight spouse is used to eating a lot, the other involuntarily also begins to 'stretch' the stomach.'
From a psychological point of view, if a wife insists on her right to a lettuce leaf, it will negatively affect her relationship with her husband. 'When a person who eats exclusively high-calorie food lives next to you, it is quite difficult to resist,' says psychologist Maria Stishova. 'What and how to eat is usually chosen by the head of the family. If you start resisting the menu that is customary for the spouse, it can cause the beginning of a breakup.'
Spouses automatically transfer their culinary preferences to children. 'Eating habits are passed from mother to child,' says dietitian Alla Slepchenko. 'Research has been conducted where overweight mothers had children who weighed more than normal. And it's not always about genes - adopted children also gained weight.'
Scientists believe that the 'contagious' effect should apply not only to obesity but also to weight loss. 'The wave of influence affects not only a person's friends, as it turned out, but also friends of their friends and their friends beyond,' believes one of the study co-authors James Fowler. 'Help one person lose weight, and it will trigger a 'snowball effect' that will affect all his surroundings.'