Fatty Food Can Weaken the Immune System

Through an experiment where mice were fed a lard-based diet over a long period of time scientists concluded that fatty food is bad for our health. Obesity is usually associated with inflammation that does not result from an infection, which simply means that the immune defences are activated unnecessarily. Ironically, the mice on the high-fat diet seem to have a less active immune system when they really need it. Fat people are at a greater risk of acquiring infection, for example in connection with an operation.

http://www.sciencedaily.com/releases/2009/12/091208132526.htm