The Science of Fasting


Fasting – A how to for 2017’s fitness craze

Sometimes, the best diet may be a diet of nothing at all.

Almost out of nowhere, we’re being recommended to fast – abstain from food – from fitness bloggers, doctors, and nutritionists. While fasting has its benefits, it also has its risks if not performed correctly. Here we list the pros and cons of fasting, and the best way for people to get started with fasting.

The Support for Fasting

In the past year, the online fitness world has been extolling the virtues of fasting, for weight loss, and even increasing one’s lifespan. Proponents of fasting claim it can also prevent diabetes, and cancer. Research has shown that fasting has been able to boost health, improve cognitive performance and extend lifespan in mice. While the research hasn’t been as conclusive in humans, there have been breakthroughs that do indicate fasting might be a solution to society’s health issues.

At the same time, we’ve been cautioned against avoiding eating for extending periods of time. As we’ve grown up and developed our eating habits, we’ve been regularly told that skipping meals leads to eating disorders, and overall, even putting on weight. 

Here, we explain how best to fast safely to maximize the benefits of fasting while avoiding long-term risks. The best way to do so is to fast intermittently – so that you’re able to fast at certain times of the day, and help limit your caloric intake for the day.

Intermittent Fasting Methods

  1. 5:2 Diet

The 5:2 method for intermittent fasting recommends eating five days a week, and limiting your caloric intake the other two days of the week. On the two “fasting days,” calories are often limited between 500-600 calories a day. While this seems easy enough to complete, developing the willpower for this level of fasting takes time and training. As well, it’s very easy to eat more than your set limit on the fasting days. For this reason, we don’t recommend this method.

  1. Eat-Stop-Eat

The Eat-Stop-Eat method is a little bit more extreme than the 5:2 diet, since it proposes that we should do a full 24-hour fast one to two times a week. This means no food between your last meal of the day to the same meal of the next day. Going from dinner to dinner without food once, or even more than once a week is extremely difficult in terms of willpower.

  1. Alternate-Day Fasting

The Alternate-Day Fasting method recommends fasting for one day after a day in which you ate normally. This is a good way to slice your caloric intake in half – if and only if, you’re able to avoid binging on the days you do eat. Long-term, this is the most extreme fasting method, and definitely the most difficult. Sleeping on an empty stomach is not easy, especially when you begin to do it multiple times a week.

  1. The 16/8 Fasting Method – Recommended

The easiest method to begin with while still getting the benefits of intermittent fasting is the “16/8” method. Here, participants are allowed to eat normally for an eight-hour period of their day, but do not eat or drink anything in the other 16 hours of their day. In the eating window, you can easily fit in 2-3 meals, and time it so that you’re fed during your work day. 

This method is best accomplished by skipping breakfast (to start your eating window later) and then eating a large lunch and dinner within the window. After dinner – you must wait until lunch again before eating again. While this sounds tough, it’s made easier by the fact that you can drink zero-calorie beverages like water, black coffee or diet sodas during the fasting period.

This method helps you get the benefits of fasting, and keeps your daily caloric intake down at the same time.

We at Rthm recommend the 16/8 method for intermittent fasting, for its ability to help you harness the benefits of fasting, without the dangers of long-term abstinence from food. With the Rthm app, you can remind yourself when to eat – even when eating on an adjusted schedule like that of intermittent fasting.