I think I know what you are talking about. Your veins shrink, your head feels funny - almost like you took an icy shower. Frankly, I don't think it's worth worrying about because it comes and goes. Does it impact your life in any significant way? Yes, eat. Eat a lot. Fasting is fun once in awhile, be eat at least once a day for most of the year.
Steak, eggs, potatoes - fruits, nuts, berries and forage. Coconut milk and potent herbs and spices. Tea instead of coffee now and teeny amounts of kelp daily. Let's see how this does! Not really had dairy much, and gut seems better for it.