摘要
开始intermittent fasting或fasting时，感到核心体温下降是正常现象——不仅仅是四肢发冷。这是身体适应过程的一部分，并不表示脂肪燃烧或甲状腺功能出现问题。随着身体逐渐适应，这种感觉通常会得到改善。
核心要点
- 在keto或intermittent fasting期间感到寒冷是正常的适应反应，并非出了什么问题。
- 禁食期间核心体温实际上会下降，不仅仅是手指和脚趾发凉。
- 感到寒冷并不意味着脂肪燃烧减少——无论体温如何，脂肪燃烧都会持续进行。
- 冷水淋浴实际上可以增加脂肪燃烧，这推翻了燃烧脂肪需要保持体热的说法。
- 维生素 B1（以营养酵母作为天然来源摄取）有助于减轻过渡期间寒冷感的强度。
- 寒冷感会随时间推移而改善，因为身体会逐渐适应禁食。
- 禁食期间的体温下降对甲状腺功能没有负面影响。
详细内容
禁食期间身体为何会感到寒冷
当你开始intermittent fasting——尤其是在早期阶段——核心体温会自然下降。这是身体在限制食物摄入时所经历的代谢适应过程的一部分。这是一种全身性反应，并不局限于四肢末梢循环不良。
脂肪燃烧不依赖于体热
一个常见的误解是，身体需要感到温暖或”充满活力”才能高效燃烧脂肪。Dr. Berg 澄清了这一点。事实上，cold exposure——例如冷水淋浴——实际上可以增加脂肪卡路里的燃烧量。体温与脂肪代谢是相互独立运作的。
如何减轻寒冷敏感性
对于在适应阶段感到寒冷不适的人，推荐补充vitamin B1。首选形式是营养酵母，它以天然全食物的形式提供 B1，而非合成补充剂。补充 B1 可以缓解过渡期，使适应阶段更加舒适。
随时间推移的预期变化
寒冷感是暂时性的。随着身体在以脂肪为燃料方面变得更加高效，体温调节也会随之改善。在初始适应期穿着更保暖的衣物是一个实用的短期策略。
甲状腺功能不受影响
禁食期间核心体温的下降并非甲状腺功能障碍的迹象。这是与禁食适应过程相关的独特生理反应，不应与hypothyroidism的症状相混淆。
涉及概念
- intermittent fasting
- keto
- fasting adaptation
- fat burning
- cold exposure
- vitamin B1
- nutritional yeast
- hypothyroidism
- core body temperature
- metabolic adaptation
English Original 英文原文
Summary
When starting intermittent fasting or fasting in general, it is normal to experience a drop in core body temperature — not just cold extremities. This is part of the body’s adaptation process and does not indicate a problem with fat burning or thyroid function. The sensation typically improves as the body adapts over time.
Key Takeaways
- Feeling cold on keto or intermittent fasting is a normal adaptation response, not a sign something is wrong.
- Core body temperature actually decreases during fasting, not just in the fingers and toes.
- Cold sensation does not mean you are burning less fat — fat burning continues regardless of body temperature.
- Taking a cold shower can actually increase fat burning, disproving the idea that heat is required to burn fat.
- Vitamin B1 (taken as nutritional yeast for a natural source) can help reduce the intensity of cold feelings during the transition.
- The cold sensation improves over time as the body adapts to fasting.
- There is no negative effect on thyroid function from the temperature drop during fasting.
Details
Why Your Body Gets Cold During Fasting
When you begin intermittent fasting — especially in the early stages — your core body temperature naturally decreases. This is part of the metabolic adaptation process the body undergoes when food intake is restricted. It is a systemic response, not limited to poor circulation in the extremities.
Fat Burning Is Not Heat-Dependent
A common misconception is that the body needs to feel warm or “fired up” to burn fat efficiently. Dr. Berg clarifies this is not the case. In fact, cold exposure — such as taking a cold shower — can actually increase the number of fat calories burned. Temperature and fat metabolism operate independently of each other.
How to Reduce Cold Sensitivity
For those who find the cold sensation uncomfortable during the adaptation phase, vitamin B1 is recommended. The preferred form is nutritional yeast, which provides B1 in a natural, whole-food form rather than a synthetic supplement. B1 supplementation can ease the transition and make the adaptation period more comfortable.
What to Expect Over Time
The cold feeling is temporary. As the body becomes more efficient at running on fat for fuel, the temperature regulation improves. Dressing in warmer clothing during the initial adaptation period is a practical short-term strategy.
Thyroid Function Is Not Affected
The drop in core temperature during fasting is not a sign of thyroid dysfunction. It is a distinct physiological response tied to the fasting adaptation process, and should not be confused with symptoms of hypothyroidism.
Mentioned Concepts
- intermittent fasting
- keto
- fasting adaptation
- fat burning
- cold exposure
- vitamin B1
- nutritional yeast
- hypothyroidism
- core body temperature
- metabolic adaptation