I've been practicing yoga for more than 10 years, a lot of Bikram hot yoga - so I feel you regarding the differences on energy level and at least how the heat and increased flow of air can help free up and clear the sinuses, and why long ago I gave up dairy, soy, and bananas - as I'd notice the decreased ability to breath and likewise my sleep would become worse - I believe because there'd be less ease of breathing while asleep.
- You might have an especially strong reaction to those foods, i.e. they produce more mucous in _you_
- You might have engaged in other mucous-reducing habits around the same time e.g. drinking more water or practicing yoga. Hard to identify a root cause in a study of one.
Getting a Neti pot (use distilled or previously boiled water only, along with adding a proper amount of non-iodized salt - Google search will give the answer) and trying that out to help clear the sinuses with warm water seems to help a lot of people as well.