Intermittent fasting is one of the most renowned diet routines followed all around the globe. It is not a new technique; various cultures around the world have been following it for centuries to regulate healthy physical and psychological levels in the body. In this regime, people have a fixed pattern of eating and fasting.
In general, we do follow a regular cycle of eating, sleeping, and repeating a similar regimen. But, in an intermittent fasting diet, the period between the two sessions of eating is more extended than usual.
How Does Intermittent Fasting Work?
Most modern diets have some or other restrictions when it comes to food choices. Some say restrict sugar while others say not carbs, and the list goes on. But, intermittent fasting does not restrict you much and gives you more freedom to eat your favorite foods.
As mentioned earlier, in intermittent fasting, there is a scheduled gap between eating and fasting. It might be that you eat for eight hours and fast for the next 16 hours. Or you may also be fasting for a day and eating the next day for a specified period.
Intermittent fasting says to eat whatever is good for health with restrictions on time and the number of calories for each cycle.
Carbohydrates, a large part of most of the diets are broken down into sugars, which acts as a source of energy. So, after consuming food, the excess sugar triggers the pancreas to release the insulin hormone into the bloodstream to regulate blood sugar. It then stores the energy in the form of fat and also balances sugar levels in the bloodstream.
So, excess insulin production can lead to excess storage of energy as fat (1). During intermittent fasting, the body gets more time to regulate insulin levels, which in turn reduces the fat.
When we fast for long or have long gaps in between meals, the cells use that fat to fuel the body with energy. Besides, the fasting may also make you feel full faster, which in turn may make you consume fewer calories.
Intermittent fasting may also exhibit mild stress on the cells and on the body. Stress may not always be a negative thing.
For example, when the muscles and other organs are under stress during a physical workout, it makes them stronger. But, here we should note that we need to give some time for the body cells to recover and become stronger after such vigorous exercises. A similar pattern may be in work during intermittent fasting.
Eating highly nutritious food that can keep our body functioning during the breaks is also essential.
Intermittent Fasting Benefits
Intermittent fasting has numerous benefits on the body. In some studies conducted on animals, fasting showed improvements in biomarkers of diseases, reduced oxidative stress, and also preserved the functions of learning and memory (2).
A similar study also told that during fasting cells, functionally adapt to enhance their ability to cope with stress and also may resist diseases. Other studies have also shown that intermittent fasting does more than just reduce the fat in the body (3).
It is known to reduce blood sugar, alleviate inflammation, improve metabolism, and even clear the toxins or damaged cells that, in turn, may lower the risk of cancer and other chronic diseases.
Intermittent fasting has numerous other benefits as well. It reduces insulin levels, which in turn may improve the functions of the brain and heart.
Intermittent Fasting Benefits
Below Listed Are a Few of the Most Recognized benefits:
Calorie restriction during intermittent fasting is known to inhibit aging factors (4). In the same paper, they also wrote about a group of Spanish home nursing residents practicing alternate-day fasting. Those people had lower age-associated morbidity and even a longer lifespan.
Inflammation is vital as it signals the immune system to repair or heal the damaged tissue and also defend against foreign invaders. However, chronic inflammation can damage healthy cells and organs, which can, in turn, accelerate the process of aging or early-age morbidity.
Intermittent is known to reduce chronic inflammation. According to a study (5), intermittent fasting triggers the release of specific pro-inflammatory cells. During fasting, these cells are in rest mode and exhibit less inflammatory actions. Another study showed that fasting could also reduce oxidative damage and improve cellular stress resistance.
3. Cardiac Health
Intermittent fasting or fasting, in general, is known to reduce blood pressure, total cholesterol, triglycerides, and LDL cholesterol (6). These can mitigate cardiac risks and also improve cardiac health.
4. Burns Fat
As mentioned above, intermittent fasting helps in lowering insulin levels, which in turn reduces fat deposited in the cells. It also prevents the deposition of new fat in the cells. These promote healthy weight loss and reduce obesity.
5. Brain Health
Lower insulin levels might also mitigate abnormalities in neurons that, in turn, decreases the risk of Alzheimer’s, Parkinson’s, and other neurological diseases. Intermittent fasting is also known to improve the brain’s ability to reorganize itself by forming new neural connections (7).
Higher insulin levels are related to obesity, diabetes, high BP, and increased triglycerides. So, lowering insulin can alleviate all these conditions. It also drops cholesterol levels that may decrease the inflammation caused by metabolic syndrome.
Intermittent fasting is known to stimulate autophagy. It thus supports the body in clearing out the old, junky, and other cell parts that are no longer in us.
Types of Intermittent Fasting
Primarily, there are six types of intermittent fasting. It is classified based on the periods of fast. They are as follows:
1. 16/8 or 14/10 Method
In this method of fasting, you must eat between a period of 8-10 hours and be on fast for the next 16 or 14 hours. In the eating period, you can eat three or more meals at your convenience. You can have dinner and skip breakfast or have proper lunch and something in the evening, later skip dinner, and then have breakfast.
For those who feel hungry after skipping breakfast or dinner or any meal during the day, you can drink water or noncaloric beverages.
Men can fast for 16 hours, while women can restrict it to 14-15 hours.
2. Eat-Stop-Eat or 24-Hour Fast
Eat-stop-eat is a 24 hour fast or starting your fast at a particular time today and ending it at the same time tomorrow. In simple terms, you fast for 24 straight hours. In general, people eat their dinner and skip whole meals the next day and then eat their dinner. You can also do it from breakfast to breakfast or lunch to lunch.
During the 24 hours of fasting, you can drink water or other noncaloric beverages. You can follow this method for one or two times a week.
It may be challenging to start straight away with 24-hour fasting; hence you may begin with 14/10 or 16/8 method.
3. Alternate-Day Fasting
In this method, you are on complete fast or eat only a few hundred calories on the days of fasting. In this method, you may have to go to bed or go through your entire day without eating, which can be difficult if you are going out for work.
It may be easy for those staying or working from home. But, for those who go out for work every day must be careful about this method. If you want to go about this method seriously, then you should have a few hundreds of calories instead of going on a complete fast.
4. The Warrior Diet
The Warrior Diet does justice to the title; it means eating a massive meal in the night and only eating small amounts of raw fruits or vegetables during the day.
The person may or may restrict themselves from eating even small amounts and feast at night. In general, the eating window should be around 4-hours. Eating whole or unprocessed foods are some excellent food options to include in this diet.
5. 5:2 Method
In this diet, you can have your regular meals for five days of the week. For the remaining two days, you must restrict yourself to 500-600 calories a day.
Here, women can eat 500 calories in those two days, while men can stick up to 600 calories a day.
During those two days, make sure that your food is highly nutritious.
6. Skipping Meals
In this method, there is no window or strict period for fasting or eating. Here, you may skip meals whenever you do not feel hungry or skip it from time to time.
You can have healthier lunch and skip dinner or a healthier breakfast and skip lunch. Either way, you skip one or two meals.
Note: Eat highly nutritious food during this time and also avoid any junk foods. Do not binge eat or excess calories in the window of eating.
[Read: Benefits of Water Fasting]
Is Intermittent Fasting Safe for Everyone?
While, in general, every healthy person or people who are trying to reduce weight or similar health conditions can follow intermittent fasting. However, a specific group of people or those with chronic conditions should avoid intermittent fasting unless suggested by your physician. Check the below groups of people who should avoid intermittent fasting in general:
- Below 18 years
- Underweight people
- Insomnia or sleep disorders
- Psychological disorders or disturbances
- Breastfeeding or pregnant women
- People with digestive disorders
You can start or practice intermittent fasting on your own. However, there are some measures that you should follow to avoid any complications or trigger any abnormalities. Below listed are a few:
- Always keep yourself hydrated.
- Make sure to add highly nutritious food – proper amounts of proteins, carbohydrates, and healthy fats.
- Do not cut your calorie intake all at once.
- Start with skipping meals or 16/8 method instead of going with much harder ones
- Create a proper diet plan by checking with a dietitian or a health expert.
- If you are on medications or treatments, check with your physician (Skipping meals or fasting while on medications can have adverse effects).
- Instead of eating heavy meals at once, eat in small portions in the window of eating.
In healthy or overweight individuals, there is only a little evidence that intermittent fasting may be physically or psychologically harmful. However, in some cases following a diet without consulting an expert or not following it properly or even due to some health conditions, it may have some side-effects. Below listed are a few:
- Digestive disorders
- Lower energy levels
- Lower concentration levels
Also, do not practice intermittent fasting for a prolonged period of time, which could otherwise reverse the benefits and lead to various health complications. Make sure to check with a dietitian or a physician to determine the duration of intermittent fasting. They can help you plan it in accordance with age, health, weight, and other medical factors.
Intermittent fasting or fasting, in general, is an age-old method. As mentioned above, alongside reducing weight, it also has numerous health benefits. However, instead of going hard with a 24-hour or longer hour diet, you can use shorter fasting.
If you are on medications, treatments, or have any underlying health conditions, you must check with a physician or a health expert before starting intermittent fasting.
1. Will Fasting Cause Muscle Loss?
Yes, fasting may reduce both fat mass and lean mass. However, there is lower muscle loss in intermittent fasting than other weight-loss diets.
2. Isn’t It Unhealthy to Skip Breakfast?
Skipping breakfast every day can be unhealthy or create abnormalities. However, doing it once in a while, such as during intermittent fasting, can be healthy.
3. How Many Days Should You Do Intermittent Fasting?
You can practice intermittent fasting for once or twice a week. It also depends on the type of intermittent fasting that you chose. However, we recommended you consult with your physician or dietitian to design the fasting plan.
4. What Can You Eat on Intermittent Fasting?
There is no restriction of foods during intermittent fasting. However, you should add highly nutritious foods and avoid anything that could cause even mild allergies.
5. How Much Weight Can You Lose in a Month With Intermittent Fasting?
In general, intermittent fasting can reduce around 0.25 kg to 0.75 kg per week. However, it does depend on the type of fasting that you chose.
6. Is It Safe for Women?
Yes, intermittent fasting is completely safe for women. But, pregnant or breastfeeding women should avoid it.