Twenty-five years ago, a research expert in obesity named Nik Dhurandhar went for a dinner party in Mumbai where he first started thinking about the possible link between obesity and a virus.

Nik Dhurandhar recalled, “I was speaking with a veterinarian who was an old family friend when he mentioned that thousands of chickens that had died from a virus had gotten very fat.” He further continued, “I said, wait a minute. You’d think a dying chicken would waste away, not the opposite. My mind began to spin. Was it possible somehow that both conditions were related?”

The phenomenon remained in his mind and he soon realized that the animals becoming infected with the common cold virus AD-36, had gained weight. When this theory was tested on more than 500 people, he observed that around 30 percent of the obese patients had already been exposed to the AD-36 virus. Since then, many follow-up studies have been conducted by other research teams who have produced similar findings.

The AD-36 virus improves blood-sugar and cholesterol levels. Dhurandhar explained, “We think the virus infects fat cells, causing them to divide and grow faster than normal; your body may produce more fat cells, but that means there’s less fat left to travel to your liver and blood.”

Dhurandhar gave the hope, “If you do have the obesity virus, it doesn’t mean you’re incapable of losing weight—it just means you’ll have to work a lot harder.”

By the next decade, the investigators hope that a vaccine will be available to inoculate people against AD-36. But one should keep in mind that genetics and lifestyle changes also play a major role.