“…Winter. There should be plenty of physical work. Eat liberally, if the prevailing wind is northerly. If southerly, increase the exercise but diminish the amount of food. Diet: The bread should be made heavier in winter than in summer. The same applies to flesh-meat, roasted meat, and the like. Pot-herbs: take cabbage, beet, celery. Avoid … red barley, purslane, endive. …When the body is healthy, illnesses are unlikely to come on during the winter. Should they do so, however, the appropriate treatment should be used, including purgation if that is necessary. Illness will only arise under strong provocation, the agents being usually of a " hot " quality…”
http://data.nur.nu/Kutub/English/Avicenna_Canon-of-Medicine_text.pdf