How can a virus make you fat

  • It has been well-known for some time that certain adenoviruses can cause obesity in humans, as well as animals. 
  • According to a paper published recently, three human adenovirus types, Ad5, Ad36 and Ad37 are linked to increased adiposity and weight gain, especially in children.
  • One of them, Ad36 is the most extensively studied adipogenic adenovirus with 30% of overweight/obese children and adults carying the virus. However, about 15-20% of lean individuals also carry the virus, which means that not all people are affected: some are more vulnerable than others, depending on their genetics and the state of their immune system. 
  • Ad36 is known to cause fat gain in at least three different ways: it increases cell membrane glucose receptors, leading to absorption of glucose by fat cells: it increases fatty acid synthase, which converts the glucose to fatty acids inside the fat cells; it increases PPAR-γ, resulting in the differentiation (conversion) of stem cells into adipocytes (fat cells)
  • Unfortunately, at the moment there is no known cure to mitigate the effects of obesity-causing adenoviruses, other than diet & exercise, even though those viruses affect at least 15% of the obese and overweight and clearly more research is needed.
  • Source: Role of adenoviruses in obesity, http://www.ncbi.nlm.nih.gov/pubmed/26352001