If you want to really know where the weight begins to increase during the holidays, this is one of the main root causes. The majority of weight gain and symptoms that occur during the holidays are resultant from “inflammation.” Basically when we eat sugar and refined foods, this creates extracellular fluid retention. This leads to inflammatory weight gain, usually by about 5-10 pounds. It also causes our immune systems to go haywire, having to deal with these inflammatory foods. This can lead to fatigue, joint pain and flu-like symptoms.