Intermittent fasting is an umbrella term used to describe eating patterns. It involves eating within a specific period of time and fasting for the rest of the day.
Though research is still being conducted to assess its ability to ensure weight loss compared to long-term calorie restriction, intermittent fasting has shown success in helping individuals lose weight.
How does intermittent fasting work?
To understand how intermittent fasting leads to weight loss we first need to understand the difference between the fed state and the fasted state.
Your body is said to be in a fed state when it is digesting and absorbing food. Typically, the fed state starts when you begin eating and lasts for 3 to 5 hours as your body digests and absorbs the food you ate. Insulin levels in the body are usually high during this period hence it is hard for your body to burn fat.
After this time span, your body goes into the post–absorptive state, during this time your body is not processing a meal. The post-absorptive state lasts until 8 to 12 hours after your last meal after which, you enter the fasted state.
It is much easier for your body to burn fat in the fasted state because your insulin levels are low. When you are in the fasted state your body can burn fat that has been inaccessible during the fed state.
Hence, our bodies do not start to burn fat until about 12 hours after a meal. This is one of the reasons why many people who start intermittent fasting will lose fat without changing what they eat, how much they eat, or how often they exercise. Fasting puts your body in a fat burning state that you rarely make it to while eating 3-5 times a day.
Types of intermittent fasting
1. Skip A Meal
This is the easiest place to start if you have never tried intermittent fasting. As the name implies it involves skipping one meal every day. When you are comfortable with this type of fast, you can then try a longer fasting period.
2. Fasts that last longer than 12 hours
It takes 12 hours for your body to enter a fasted state and become more effective in using stored fat. For this reason, if you aim to lose weight, it is recommended that you fast for at least 12 hours every day.
After you are comfortable with fasting for 12 hours daily, you increase the length of your fast.
The 16/8 method is very popular and convenient. Here, you fast for 16 hours in a day and eat during the 8-hour window. Individuals with more experience can try the 20/4 fast.
3. Alternate Day Fasting
Alternate day fasting refers to when you fast for one whole day, then eat normally the next day.
Below are 2 ways that you can practice alternate day fasting:
- You can fast completely on fasting days, only consuming water
- You can eat super small meals up to 25% of your regular caloric intake. This equals about 500-600 calories for the average person. However, you should not include sugar or starches in your meals. This option is considered “fasting-mimicking,” and there’s a small study that suggests it can help with weight loss and support heart health.
Alternate-day fasting is one of the more extreme approaches to fasting, and it can be difficult for some people to practice.
4. Water Fast
As the name implies it involves fasting for 24 hours while drinking water. This type of intermittent fasting is good for bringing the body into a state of ketosis within a short period. Before you go on a water fast, it is important that you consult your doctor.
This is not a sustainable lifestyle change and we do not recommend that you go on water fasts that last for long periods.
Benefits Of Intermittent Fasting
There are many reasons why you should try intermittent fasting. These reasons include:
- Weight loss while maintaining lean muscle mass
- Increased human growth hormone, which helps with fat loss
- Improved appearance of your skin
- Improved blood sugar and insulin levels
- Longevity and protection from chronic illness
- Increased brain health
- Reduced cholesterol levels
Despite the many benefits of intermittent fasting, here are some cons of intermittent fasting:
- Stomach ulcer
- Hormonal imbalance
- Damaged metabolism
- Consumption of unhealthy meals during the feeding window
Intermittent fasting like many other diets has its pros and cons. To get the best results while fasting, educate your self on fasting before you begin. Also, start slow by skipping one meal a day and build your self-control.
Lastly, accept that while intermittent fasting may help you lose weight, a lifestyle change is necessary to keep the weight off.