From the article:
The results show that the cells that are affected by interleukin-6 produce substances that not only affect our sense of hunger and fullness but also control the body’s ability to burn fat. “Interleukin-6 increases levels of substances in the brain that trigger weight loss, which could explain why high levels of this molecule lead to weight loss,” says doctoral student Erik Schéle, who is presenting the results in his thesis.
It is known that our normally low levels of interleukin-6 in the brain increase dramatically during an infection, typically accompanied by reduced hunger and fatigue.
“Our previous findings would indicate that interleukin-6 can play a key role in regulating the metabolism of healthy individuals too,” says Erik Schéle.
“This is clearly substantiated by our finding that mice which lack interleukin-6 get fat, and that the metabolism of rats injected with interleukin-6 directly into the brain increases.”