In some individuals dairy products coat the mucus that is already present making it feel thicker and sticker. Whether it is the fat or another component of the dairy product is not known. Drinking plenty of water will help to thin the mucus so that it moves more easily. As long as you are not on a fluid restriction you should be drinking 6 to 8 8-ounce glasses of non-caffeine non-alcoholic fluid daily.
As for the fats in other foods, it would be wise to keep a diary of mucus produced and all foods ingested within the preceding 24 hours.
Thank you , that makes sense.