There is an abundance of diets, some more popularized than others. For example the Atkins diet has been heavily popularised in mainstream media throughout the world, particularly in the 1960s in the West when food culture started changing and people started gaining excess weight as a result of this. Particularly in the United States, a large focus began to shift onto how to lose weight and stay slim, hence the beginning of the diet revolution.

市面上有各式各樣的飲食法，有些比其他更為普及。例如「阿特金斯飲食法」（Atkins diet）在全球主流媒體中廣泛傳播，特別是在 1960 年代的西方，當時飲食文化開始轉變，人們因此體重過重。尤其在美國，大眾開始集中關注如何減重和保持苗條身形，於是掀起了所謂的「節食革命」。

A ‘diet’ by definition is a ​special course of food to which one restricts oneself, either to lose weight or for medical reasons ​according to the Oxford Dictionary. So in essence, a diet is an eating habit with its aim set as weight loss. There have been periods in the diet revolution associated with particular diets, for example the Atkins diet in 1960s, the Weight Watchers diet in the 2000s etc and the Ketogenic diet in more recent times.

根據《牛津字典》的定義，「diet」是指一種特別的飲食方式，為了減重或醫療原因而限制自己進食的種類與份量。換句話說，節食本質上是一種以減重為目標的飲食習慣。在節食革命的不同階段，會有特定飲食法的流行，例如 1960 年代的阿特金斯飲食法、2000 年代的 Weight Watchers（體重觀察者）飲食法，以及近年的生酮飲食法。

But how effective are diets? Diets, as a tool for weight loss, have mixed results. People who are more able to adhere to the diet, will in most cases successfully lose weight. Whilst conversely, individuals who have poor adherence are more likely to maintain their weight or in some cases increase their weight. Those who are unable to adhere to the diet often cite negative emotions such as feelings of failure, increased hunger and more mood swings.

那麼，節食到底有多有效呢？作為減重工具，節食的效果參差不齊。能夠嚴格遵守飲食計劃的人，大多能成功減重；相反，那些難以堅持的人，不但更可能維持原本體重，有時甚至會變得更重。無法堅持的人常常提到一些負面感受，例如挫敗感、饑餓感增加，以及情緒波動更大。

This is not just unique to those who fail to stick to the diet though, in fact even those who successfully lose weight cite a combination of negative feelings associated with the diet plan. Doesn’t sound too good does it? So how can you lose weight effectively and enjoyably? The jury is out. Some tout intensive exercise as the best fat loss method, but you’d have to run a lot of miles to burn off that cheeseburger. It’s all about ​what​ you’re putting in your body, and as scientific research has more recently discovered - ​when​ you’re putting it in your body.

事實上，這種情況並不僅限於無法堅持的人；即使是成功減重的人，也會提到節食計劃帶來的種種負面感受。聽起來不太吸引，對吧？那麼，怎樣才能既有效又愉快地減重呢？答案還沒有定論。有人認為高強度運動是最佳的減脂方法，但要消耗掉一個芝士漢堡的熱量，你得跑很長很長的路。關鍵不只是吃甚麼，而且還包括甚麼時候吃，這也是科學研究近年發現的重要因素。

What Is Intermittent Fasting
什麼是間歇性斷食

You may have heard of various forms of intermittent fasting - the 5:2 diet, the time controlled eating diet, the 16 hour window diet etc. These are all under the bracket of intermittent fasting, and from now onwards I will refer to them not as a ‘diet’ but as an eating pattern, because that is essentially what it is.

你可能聽過不同形式的間歇性斷食，例如 5:2 飲食法、時間控制飲食法、16 小時進食窗口法等。這些都屬於間歇性斷食的範疇，而從現在開始，我不會再稱它們為「飲食法」，而是稱作「飲食模式」，因為它的本質就是如此。

Unlike a typical ‘diet’, intermittent fasting does not give guidance on what you should be consuming, only when you should be consuming it. It is fundamentally based on the concept that historically humans do not ‘graze eat’ i.e. eating continuously throughout the day and evening; and this can in fact be detrimental to your digestive system.

與一般的「飲食法」不同，間歇性斷食並不規定你該吃什麼，而是規定你該在什麼時間進食。它的核心理念是基於人類在歷史上並不「全天候進食」，即不會從早到晚持續吃東西；事實上，這樣做對消化系統可能有害。

Historically, humans were hunter gatherers who would go through long periods of famine often during the winter when there were few crops or when there were no animals to kill for sustenance. After a prolonged period of famine, they would enter a feasting period in which they would consume a large meal shared with their tribe. This cycle would then repeat itself.

在歷史上，人類是狩獵採集者，在冬季農作物稀少或沒有獵物可供食用時，往往經歷長時間的飢荒。在長期的飢荒之後，便會進入一個盛宴期，與族人共享一頓豐盛的餐點。這種循環會不斷重複。

When you compare this with how humans eat today it could not be more different. We live in a fast food culture: calorie dense food is highly accessible, cheap and palatable. It is common for most to eat upon rising and continue eating every couple of hours until sleep. This eating pattern can cause overeating, due to the extended eating window which can lead to an increased appetite and food cravings. This can then lead to weight gain and obesity.

將這與現代人的飲食方式相比，可謂天差地遠。我們生活在一個快餐文化中：高熱量食物隨手可得、價格便宜且味道誘人。許多人一醒來便開始進食，並在一天中每隔幾小時就吃東西，直到入睡為止。這種延長的進食時段會導致暴飲暴食，刺激食慾與食物渴望，進而造成體重增加與肥胖。

Alongside the increased risk of obesity, eating continuously throughout the day can wreak havoc with your digestive system. It can take anywhere between six to eight hours for your body to properly digest the food you have consumed. So think about it this way - if you are snacking until midnight and then wake up at 8am and eat breakfast, it is likely that the food you ate the night before has not even been properly digested yet. In extreme cases, this can cause liver toxicity, irritable bowel syndrome (IBS), bloating, inflammation and other undesirable health issues.

除了增加肥胖風險外，全天持續進食還會對消化系統造成嚴重影響。人體需要大約六至八小時，才能將攝入的食物徹底消化。換個角度想，如果你一直吃零食到午夜，早上八點起床又吃早餐，很可能前一晚的食物還未完全消化。在極端情況下，這可能引發肝臟中毒、腸躁症（IBS）、腹脹、發炎及其他不良健康問題。

What Happens To Your Body When You Fast
斷食時的身體會發生什麼

Fasting has been shown to improve biomarkers of disease, reduce oxidative stress, preserve learning and memory functioning, increase muscle mass and reduce body fat - according to recent research undertaken by the US National Institute of Health (1). This of course depends on a plethora of variables aligning, for example if you are eating large quantities of junk food more so than usual, you will not experience these benefits. However, if you are eating a healthy balanced diet, get sufficient exercise and commit to the time frames of the fasting and eating windows - you will start to notice some of the amazing benefits of intermittent fasting.

根據美國國家衛生研究院（NIH）近期的研究，斷食已被證實能改善疾病生物標記、減少氧化壓力、維持學習與記憶功能、增加肌肉質量及減少體脂肪。當然，這些效果取決於多種因素的配合，例如，如果你比平時攝取更多垃圾食品，就不會體驗到這些好處。然而，如果你保持健康均衡的飲食、適量運動，並遵守斷食與進食時間，你將會開始感受到間歇性斷食帶來的驚人益處。

The most common form of intermittent fasting is the 16:8 fast, which involves fasting for 16 hours typically during the night time until around midday and then eating until the evening. Essentially you’re cutting out breakfast. This has been shown to suppress the appetite and decrease stomach capacity, which causes feelings of satiety to occur sooner into eating thus resulting in a smaller food intake. So for individuals that are trying to lose weight, fasting can be a great tool.

最常見的間歇性斷食形式是 16:8 法，即每天斷食 16 小時，通常從晚上開始直到翌日中午左右，再在剩下的 8 小時內進食。基本上，就是不吃早餐。研究顯示，這種方法能抑制食慾、減少胃容量，使人在進食過程中更快感到飽足，從而降低總進食量。對於想減重的人而言，斷食是一個非常有效的工具。

There are several theories about why fasting provides physiological benefits, one hypothesis being that cells are under a moderate level of stress during a fasting period. This results in cells being forced to adapt by improving their ability to manage stress and resist disease. Studies undertaken by the US Institute of Health have shown a similar physiological response when an individual is undertaking intense exercise, in which the cardiovascular system is under a similar level of stress. The body responds by effective adaptation, similarly to what occurs during intermittent fasting.

關於斷食為何能帶來生理益處，有幾種理論，其中一種假設是，在斷食期間，細胞處於適度壓力之下，迫使它們提升應對壓力和抵抗疾病的能力。美國國家衛生研究院的研究顯示，這種反應與人在進行高強度運動時相似，此時心血管系統承受類似程度的壓力，身體會通過有效適應來應對，就像間歇性斷食時所發生的情況一樣。

Now going back to the initial point of question, intermittent fasting is not a diet. It is not similar to the Atkins diet or the South Beach diet on the basis that it does not state ​what y​ ou should eat, only ​when​. This does not mean you are able to gorge on high calorie treats all day and expect to lose weight as long as you’re fasting. But it does mean that you have flexibility in what you decide to eat, which has been shown in numerous studies to increase adherence to losing weight.

回到一開始的重點，間歇性斷食並不是一種飲食法。它與阿金飲食法（Atkins Diet）或南灘飲食法（South Beach Diet）不同，因為它不規定你該吃什麼，而是規定你該在什麼時間吃。這並不代表你可以在斷食之外的時間無限制地吃高熱量零食，還期待能減重。但它確實給予你更多選擇食物的靈活性，而研究顯示，這有助於提高減重的持續性與成功率。

You will also notice having a decreased appetite which will help you to reduce your caloric intake leading to weight loss. All you need to do is fast for 16 hours a day, eat for 8 hours a day and be as healthy as you can. No absurd restrictions, no mood swings or negative thoughts, just a simple shift in your eating pattern.

你還會發現食慾下降，這有助於你減少熱量攝取，進而達到減重效果。你所需要做的，就是每天斷食 16 小時、進食 8 小時，並盡可能保持健康的飲食習慣。沒有荒謬的限制、沒有情緒波動或負面情緒，只是單純改變一下進食模式。

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Research & Resource

Intermittent fasting: the science of going without

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This article was originally published on our website in Jan 2019 before recent rebranding.