Before you blame Christmas weight gain on the pavlova, consider whether it could actually be because your body has a brand new organ.
The 'mesentery' isn't new, but its importance has only just beginning to be understood. It connects the intestine to the abdomen, and has long been thought of as a collection of fragmented parts.
In 2012 it was found to be a single structure, and further research has now seen it classified as a previously unrecognised organ - the 79th known to medical science.
"In the paper we are now saying we have an organ in the body which hasn't been acknowledged as such to date," says J Calvin Coffey, professor of surgery at the University of Limerick's Graduate Entry Medical School.
The findings have caused excitement in the medical community, as this is the basis for a whole new area of surgery and science.
It will change how medical students around the world are taught about the digestive system. One of the world's most famous medical textbooks, Gray's Anatomy, has been updated to include the mesentery's new position.
Prof Coffey hopes the reclassification could be the key to treatment of abdominal and digestive disease, meaning less invasive surgeries, lower costs, fewer complications, faster patient recovery and lower costs overall.