Is obesity contagious? The surprising news that some obese children are more apt to carry a common cold virus than slimmer children has many people wondering. If the potential link between the adenovirus 36 and childhood obesity turns out to be real, then someday new obesity treatments might be tailored to attack the virus to treat or prevent childhood obesity, an epidemic that affects 17 percent of American children and teenagers.

Is Child Obesity an Infectious Disease? – US News and World Report