Why does my acupuncturist tell me not to eat or drink cold stuff?
Acupuncture works with Qi(energy), and Qi comes from the foods we intake. Our digestion system digest them, turn them into "stomach Qi", and then it will be distributed to each and every body parts through different route. When we eat or drink cold things, our body will try to warm it up, cause Qi to over concentrate in stomach, and lack in other route. Stomach will use up a lot of Qi just to maintain it's normal temperature.
At this point:
1) If your Qi level is pretty good, every route that Qi goes through are smooth and stable, then you might be fine. After stomach work extra hard to warm itself up, you might even start to feel hot, because it takes a while for it to calm down from hard working mode. If this happen too much, there's a possibility that stomach will stay hard working and never calm down, consume a lot of Qi, or over distribute Qi to some body part. That's when you'll start to feel like you need to make an appointment with your acupuncturist.
2) If the Qi level is a bit low, or some of the route that Qi goes through isn't that smooth, it might start to have problem. In the normal situation, the Qi flow is strong enough to support these parts, but now stomach is using up a lot of Qi supply, and not sending enough Qi out, so these parts start to have stagnation. After the stomach has successfully warm itself up, and still stay in hard working mode, it might start to over distribute Qi to all routes. But some of those routes are stuck now, so Qi can only go to other body parts: If it goes to head too much, it cause headache; if it goes down to intestine too much, that's diarrhea... etc.
3) Of course, if the stomach itself become weak by overworking, that cause over all weakness of whole body.
Ps. This is how food coma happens too. Slight over concentration of Qi in the stomach that cause a bit lack of Qi in the head can happen when you eat too much as well.
How cold is considered cold?
Base on the mechanism above, lower then body temperature is considered cold. The colder it is, the more it will effect the body.
Why are some foods considered cold too?
There are some food that cause effects similar to the real cold food or drinks; and there are some other foods that can help on "heat syndrome". These foods are classified as "cold food" in Traditional Chinese Medicine (TCM). They are not as bad as the real cold things, in some cases they can even be used to adjust body condition.
Orange Acupuncture, Winston Wang