FOX: Obesity can be "caught" as easily as a common cold from other people's coughs, sneezes and dirty hands, scientists are set to declare today.

The condition has been linked to a highly-infectious virus which causes sniffles and sore throats.

Professor Nikhil Dhurandhar said the virus, known as AD-36, infects the lungs then whisks around the body, forcing fat cells to multiply and also causing sore throats.

"When this virus goes to fat tissue it replicates, making more copies of itself and in the process increases the number of new fat cells, which may explain why the fat tissue expands and why people get fat when they are infected with this virus," Dhurandhar said.

In one test, a third of obese people had the rare and highly contagious virus compared to just 11 percent of thinner people. Weight gain can last three months until the body has built up resistance to the bug.

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