A lot of people were surprised over the findings of the obesity study published in The New England Journal of Medicine in 2007. It alleged that being fat is a "socially contagious" disease.

The co-author of the study, Dr. Nicholas Christakis of the Harvard Medical School, explained that a person was 37 percent more likely to become obese if he or she had a fat spouse, 40 percent more likely to get hefty if he or she had overweight siblings, and 57 percent more likely to turn tubby if he or she had chubby friends. This is supposedly because we're likely to eat what our loved ones are eating - even if they're grabbing unhealthy grub.