持續千百年的貧窮造成缺肉、少油、低卡、冬季供暖不足的中原地區形成的傳統、習慣

AI：Feeling cold on a vegan diet is a common experience。

AI: Feeling cold on your period is common, driven mainly by plummeting progesterone and estrogen levels after ovulation, which causes blood vessels to constrict and reduces blood flow to your extremities. Prostaglandins, released to shed the uterine lining, can also impact the hypothalamus (body’s thermostat) and cause chills.

在嚴重營養不良的情況下 cold1 + cold2，喝熱水，避免冰水是自然的。

但現代已經是營養過剩，食肉過剩，取暖無憂的時代。