The Facts About Cheese
A lot of fighters prefer to cut down or eliminate cheese from their diet, especially as they are training before a fight. The reason for this is most people have some amount of lactose intolerance, which means a slight (or more than slight) allergy to dairy products. This results in mucus in the nose, sinus and chest, and makes it harder to get complete breaths.
Note also that dairy products, like meat products, still contain those concentrations of pesticides and hormones that we are trying to avoid for optimal health and performance.
If you experiment with cutting down on cheese and dairy, you will notice how you can breathe more clearly, and can regain your breath during exercise much more quickly.