How does intermittent fasting work?

Intermittent fasting simply revolves around creating an eating pattern where you designate periods for fasting and eating. Many people can attest that this dietary method is effective in losing weight. 

Historically speaking, fasting is not new to us. Our ancestors were fasting since the beginning of time, and it can actually help in longevity. While our ancestors were forced to fast due to limited resources and technology, intermittent fasting is the modern way to do fasting and reaping all the essential health benefits it encapsulates. 

Intermittent fasting process

Restricting food is the main concept of intermittent fasting. When you designate more time to digest food, you are technically allowing your body to use your stored fats to convert as energy. Although glucose from carbohydrates is used mainly as a fuel source, your boy will burn fat for energy when glucose is not available. Usually, this happens when you are eating less food. 

Moreover, alternate eating and fasting can help you boost your metabolism. As you know, metabolism refers to the process by which the body changes food and drink into energy. During metabolism, the calories in food and drinks combine with oxygen in order to produce the energy that your body needs. While you are fasting, your body exhausts your sugar stores and burns your fat; hence, this explains weight loss through intermittent fasting [1]. 

7 ways to make intermittent fasting work

Losing weight almost always requires diet and exercise to go together, but there are ways to forego the latter and still attain your goal.

Intermittent fasting has several methods to make it work on your body based on your capabilities and lifestyle. These ways are inclining toward a proper eating and fasting schedule. Check out these seven (7) ways: 

Fasting for 12 hours 

The rule for doing intermittent fasting under this strategy is simple. You just need to fast strictly for 12 hours a day. In fact, fasting for around 10 to 16 hours allows your body to convert fat stores into usable energy [2]. The 12-hour fast method generally works for beginners because of its small fasting window. You may perform the fasting at night while you are asleep and just consume a relatively fewer amount of calories compared with your usual ones. One good example of this is if you choose 7pm to 7am as your fasting schedule. The majority of your 12-hour fast is happening while you are sleeping, much easier to abide by. 

The 16:8 method

With 16-hour fasting, you are giving yourself an 8-hour window for eating under the 16:8 intermittent fasting method. It is also called the Leangians diet, where you basically fast for 16 hours and eat within the 8 hour-window. 

There is a slight difference between men and women with the 16:8 method. Men should fast strictly for 16 hours, while women do it for 14 hours. This intermittent method is helpful for people who have tried the 12-hour fast method, but found that it did not work out. 

People who do the 16:8 method usually finish their last meal by 8pm and then skip breakfast the next day and have no food intake until noon. This is actually backed up by a study where it suggests that having an 8-hour feeding window can reduce obesity, inflammation, diabetes and liver disease [3]. 

The 5:2 diet 

If you wish to follow the 5:2 diet or also called the Fast diet, you must fast for 2 days a week with a low-calorie intake and eat healthy foods for the remaining 5 days of the week. Men generally consume 600 calories, and for women, it is around 500 calories for their 2-day fasting. 

Don’t worry because you don’t have to choose two consecutive days to fast for the week. You can choose alternate days or even a longer period, like Monday and Friday, for your two days of fasting. There must be at least one non-fasting day between the fasting days.

The 5:2 diet can be useful for overweight and obese women as they can consistently reduce their weight through calorie restriction and fasting. It can also reduce insulin levels and improve insulin sensitivity for people suffering in this health area. 

Almost 4.8 percent of body weight and 8.0 percent of total body fat for women lost, according to a study when they followed the 5:2 diet. However, this result may bring you back to your original weight when you neglect and keep your eating habits. 

Eat-Stop-Eat diet

The Eat-Stop-Eat diet suggests fasting completely for one to two days a week. Meaning you must not eat for 24 hours. Some examples are not eating from breakfast to breakfast the next day or lunch in the same way. This is slightly extreme, but you still can have water, low-sugar tea, and other calorie-free drinks even if you are on your fasting day. 

You can opt for your usual eating patterns on your non-fasting days or reduce your calorie intake, depending on how you can tolerate it and also based on your weight goal, but don’t overdo it. 

Fasting for 24 hours is a big challenge. It may cause several side effects, like fatigue, headaches or irritability. Rest assured that you will eventually tolerate these side effects, and they become less after weeks of doing the Eat-Stop-Eat diet. 

Meal skipping

Here, you can just simply skip meals. The meal-skipping method is perfect for beginners with its less complex rules and lower tolerance. You can skip whichever meals you feel not eating based on your level of hunger or time restraints. Take note that you have to eat nutritious meals at each meal you choose to consume. By skipping meals, you can monitor your body’s hunger signals and use them to regulate your food intake

Alternate-day fasting

Here’s another variation of intermittent fasting that can possibly work for you. The alternate-day fasting suggests fasting every other day of the week. In this method, you should choose which days to eat or which not. Eating and food restriction is practised each day alternately, whether you fast every Monday, Wednesday and Friday, and the rest you will be eating with 25 percent of your daily calorie needs. 

Some people choose to completely avoid eating solid foods for their fasting days. While the rest follow the 25 percent calorie rule, which can be around 500 calories for your fasting days.

A study proved that alternate-day fasting is effective for weight loss, and it can also help in boosting heart health. Over 5.2 kilograms or 11 pounds have been lost for people doing alternate-day fasting within 12 weeks [4].

The alternate-day fasting can be quite challenging for most people, especially as it is also the most extreme form of intermittent fasting. This method will not work for beginners and for those with medical conditions. 

The warrior diet

This is another extreme form of intermittent fasting. The warrior diet requires you to eat very little, usually just raw fruits and vegetables. You must also follow a 20-hour fasting window and eat one large meal at night. Your feeding time is restricted to 4 hours only. 

The warrior dieters claim that we are natural nocturnal eaters. When we eat at night, our body allows us to gain essential nutrients in line with our circadian rhythms. Considering that the warrior diet can be that difficult to sustain, this is only recommended for those people who have tried the basic methods of intermittent fasting. 

Benefits of intermittent fasting

Fasting generally helps in weight loss as it can produce ketosis, which refers to a process of breaking down fats instead of glucose. In fact, fasting can give you the same results as when you do a typical low-calorie diet. Although fat loss is the major benefit of intermittent fasting, it isn’t the only benefit of it.

Intermittent fasting surprisingly supports your brain health, specifically in boosting your brain function. It can enhance your metabolic, cellular and circadian mechanisms that lead to anatomical and functional changes in your brain. 

Moreover, intermittent fasting can reduce your blood pressure. In a study, this diet can significantly lower high blood pressure on a short-term basis, and it can lower your cholesterol. A high level of cholesterol puts you at risk of developing multiple fatal diseases, including heart disease and stroke. Different intermittent fasting is said to be effective in lowering LDL, among its other benefits in cardiometabolic health. Doing any intermittent fasting can lead you to lowered levels of fasting glucose, fasting insulin and leptin and reduced insulin resistance. Other benefits of it are decreased levels of leptin and increased levels of adiponectin [5].

Additionally, following an intermittent diet can deliver both cardiovascular and metabolic benefits to you. It decreases the levels of triglycerides and blood sugar levels. Experts suggest that it can also reduce the risk of cancer by slowing down the cancer cells from adapting and spreading in your body. 

The bottom line: 

Although the general concept of intermittent fasting is food deprivation in a sense, overdoing it won’t do you any good. It is a matter of distinct food intake regulation, depending on your lifestyle and habits. An intermittent fasting method that works for someone may not work for you. It is better to start with small steps before doing extreme intermittent fasting variations. 

Resources: 

[1] https://www.hopkinsmedicine.org/health/wellness-and-prevention/intermittent-fasting-what-is-it-and-how-does-it-work
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3680567/ 
[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3491655/ 
[4] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3833266/ 

Photograph: Nok Lek/Shutterstock
https://health.ucdavis.edu/blog/good-food/intermittent-fasting-benefits-how-it-works-and-is-it-right-for-you/2022/02

[5] ​​ https://jamesclear.com/the-beginners-guide-to-intermittent-fasting 

The information included in this article is for informational purposes only. The purpose of this webpage is to promote broad consumer understanding and knowledge of various health topics. It is not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of your physician or other qualified health care provider with any questions you may have regarding a medical condition or treatment and before undertaking a new health care regimen, and never disregard professional medical advice or delay in seeking it because of something you have read on this website.