Intermittent fasting is a pattern of eating that alternates between periods of fasting and non-fasting. Occasionally fasting has been shown to reset a person’s internal clock and produce several health benefits.
What Is Intermittent Fasting?
Intermittent fasting is a pattern of eating that alternates between periods of fasting and non-fasting. It is not a diet, but rather a pattern of eating that regulates when and how much to eat. It is a way of scheduling your meals, so it does not dictate what foods you should or shouldn’t eat, but when you should eat them.
Intermittent Fasting Alters Your Internal Clock
Intermittent fasting may change the internal clock, also known as the circadian rhythm, by shifting the timing of when certain hormones are released. The circadian rhythm is controlled by a group of cells in the brain called the hypothalamic suprachiasmatic nucleus (SCN) that uses cues from the environment, such as light and temperature, to synchronize the body’s internal clock with the external day-night cycle.
When we eat, our body releases hormones such as insulin and glucose that can affect the timing of the circadian rhythm. Intermittent fasting can change the timing of when these hormones are released, which can shift the internal clock.
For example, during a fast, the body’s insulin levels drop, which can lead to an increase in the production of a hormone called glucagon. Glucagon helps to break down stored glycogen in the liver and release glucose into the bloodstream, which can help to maintain energy levels during the fast. This shift in hormones can lead to changes in the timing of when certain cells in the body are active and when they are not.
Additionally, Intermittent fasting can also influence the release of the hormone melatonin which is responsible for regulating sleep-wake cycle. Melatonin level increases in the evening, signaling the body to prepare for sleep and decreases in the morning, signaling the body to wake up. Intermittent fasting can affect the timing of melatonin release, which can lead to changes in the sleep-wake cycle.
Benefits of Intermittent Fasting
Intermittent fasting has been studied for its potential health benefits, which may include weight loss, improved insulin sensitivity, lower inflammation, and a reduction in the risk of certain diseases such as type 2 diabetes, heart disease and cancer.
Some people use intermittent fasting as a way to lose weight or improve overall health, while others may use it for religious or spiritual reasons. Intermittent fasting has been studied for its potential health benefits, which may include:
- Weight Loss: Intermittent fasting may lead to weight loss by reducing calorie intake and increasing feelings of fullness.
- Improved Insulin Sensitivity: Intermittent fasting may improve insulin sensitivity, which can help to lower the risk of type 2 diabetes.
- Lower Inflammation: Intermittent fasting may lead to lower inflammation levels in the body, which can help to reduce the risk of chronic diseases.
- Increased Longevity: Intermittent fasting may increase lifespan by promoting cellular repair processes and reducing oxidative stress.
- Improved Brain Function: Intermittent fasting may improve brain function by increasing the growth of new neurons and protecting against age-related cognitive decline.
- Lower Risk of Chronic Diseases: Intermittent fasting may lower the risk of chronic diseases such as heart disease, cancer, and Alzheimer’s disease.
Intermittent Fasting Methods
There are several different methods of intermittent fasting, but the most popular include the 16/8 method, where you fast for 16 hours and eat during an 8 hour window, and the 5:2 diet, where you eat normally for 5 days and restrict calories to 500-600 for the other 2 days.
While practicing intermittent fasting, it is important to maintain a balanced diet including all the essential nutrients, vitamins and minerals. It’s also important to listen to your body and adjust the method of fasting that works for you. Some people may find it challenging to fast for long periods of time, and for them shorter fasting periods may be more suitable.
There are different methods of intermittent fasting, with some being more restrictive than others. Some popular methods include:
The 16/8 Method
The 16/8 method is a type of intermittent fasting where a person fasts for 16 hours and eats during an 8 hour window. This is the most popular and widely-used method of intermittent fasting.
The 16/8 method is also known as the Leangains method, named after its creator, Martin Berkhan, who popularized the technique in the fitness and bodybuilding community.
The most common way to follow the 16/8 method is by skipping breakfast and eating the first meal of the day at noon, then having lunch and dinner within the next 8 hours, and then not eating anything until the next day’s lunch. For example, if you finish dinner at 7 PM, you would not eat until 11 AM the next day. This means you would be fasting for 16 hours and eating during an 8-hour window, typically between 11 AM and 7 PM.
This method of intermittent fasting is considered to be less restrictive, as it allows for a larger eating window and allows for more flexibility in terms of meal timing. Additionally, it is easy to follow as it aligns with the natural pattern of hunger and fullness, typically being hungry in the morning and less hungry at night.
The 5:2 Diet
The 5:2 diet is a type of intermittent fasting that involves eating normally for five days a week and restricting calories to 500-600 for the other two non-consecutive days. On the two “fasting” days, a person’s calorie intake should be limited to about a quarter of their typical intake, or about 500-600 calories for women and 600-800 calories for men. The remaining five days of the week are considered “eating” days, and a person can eat whatever they want.
The 5:2 diet was popularized by Dr. Michael Mosley, who wrote a book about the diet in 2012. The diet is based on the idea that reducing calorie intake on certain days can have health benefits, such as weight loss, increased insulin sensitivity, and improved cardiovascular health.
Alternate-Day Fasting (ADF)
The Alternate-Day Fasting (ADF) method is a type of intermittent fasting where a person alternates between days of normal eating and days of calorie restriction or complete fasting. This method involves eating normally one day, then either restricting calories to about 25% of normal intake or fasting completely the next day, and then repeating this pattern.
The ADF method is considered to be more restrictive than other forms of intermittent fasting, such as the 16/8 or 5:2 method, as it requires a person to either significantly restrict their calorie intake or to fast completely on certain days.
The ADF method was popularized by Dr. James Johnson, who has written several books on the topic and conducted research on the benefits of ADF. Studies have shown that this method can lead to weight loss, improved insulin sensitivity, and improved cardiovascular health.
The Eat-Stop-Eat method is a type of intermittent fasting that involves complete fasting for 24 hours one or two times a week. This method involves eating normally for several days, then not eating anything (except for water, tea, and other non-caloric beverages) for 24 hours, and then returning to normal eating.
The Eat-Stop-Eat method was popularized by Brad Pilon, who wrote a book on the topic and has conducted research on the benefits of intermittent fasting. It is considered a more restrictive form of intermittent fasting, as it requires a person to completely abstain from food for a full 24 hours.
The Eat-Stop-Eat method has been shown to promote weight loss, improve insulin sensitivity, and improve cardiovascular health.
The Warrior Diet
The Warrior Diet is a type of intermittent fasting that involves eating one large meal at night, while eating small amounts of raw fruits and vegetables during the day. This method was popularized by Ori Hofmekler, who wrote a book on the topic and has conducted research on the benefits of intermittent fasting. The Warrior Diet is based on the idea that human beings are evolutionarily adapted to eating one large meal at night, as our ancestors would hunt and gather food during the day and then consume it all at once in the evening.
Under the Warrior Diet, a person would eat small amounts of raw fruits and vegetables during the day, and then eat one large meal at night that consists of protein, healthy fats, and complex carbohydrates. This meal should be eaten between 5 and 7 p.m. and should be the last meal of the day.
The Warrior Diet is claimed to promote weight loss, improve insulin sensitivity, and improve cardiovascular health.