Different Types of Fasting Explained

31st October 2022

Different Types of Fasting Explained

Matthew Lee

Fasting is more popular than ever. Much research has gone into the different forms of fasting to better understand its impact on our diet and nutritional intake. 


However, as with many nutrition protocols, knowing the right one for you can seem daunting and confusing. It can often leave people with the feeling of not knowing which one is best for them or where they should start.


Mechanisms of fasting

1. Fasting means the body is pushed into a slightly stressed state or hormesis. This hormetic effect results in the body responding to make itself more efficient, the same way the body does in between exercises. This can improve the body, including cellular health, and immune balance, and reduce disease markers.

2. The body's preferred source of energy production is glucose from carbohydrate foods. When we fast, the body's glucose storage runs low, so the body switches to fat for energy. This switch can encourage excess weight loss, and enhance our energy, focus, and overall vitality. It also makes our cellular power stations healthier, particularly the mitochondria. This works by shortening your eating window and reducing your overall food intake. A simple and hassle-free way to manage weight.


Different types of fasting

  • Time-restricted eating. This involves fasting every day for 12 hours or longer and eating in the remaining hours. A popular example is the 16/8 method. This requires a daily 16-hour fast and an 8-hour eating window wherein you can fit your meals.
    • The 5:2 diet. The 5:2 diet involves eating as you normally would for 5 days a week and restricting your calorie intake to 500–600 on the remaining 2 days.
      • Eat Stop Eat. Eat Stop Eat involves a 24-hour fast once or twice per week.
        • Alternate-day fasting. The goal here is to fast for 24 hours every other day.
          • Fasting mimicking diet. A 5-day plan with meal replacement foods formulated to simulate the fasting state while providing nutrients and calories.


            All of these show the similar benefits conferred on the body from fasting. There is no evidence one is better than the other. It really is which one you prefer and can work with effectively. 


            There is a risk of fasting too much and finding that 'sweet spot' is different for everyone. This 'sweet spot' is at the point where there is a positive metabolic switch to fat burn, but it does not move beyond hormesis to overstress the body. Individuals may have a changing 'sweet spot', which may be affected by other stresses (you can check this by tracking HRV), such as emotional distress or illness. Women in fasting protocols may be affected by hormonal changes such as time in the menstrual cycle. 


            For this reason, Limon recommends her clients ‘Time-restricted eating’, because of its flexibility. Limon notes that you can start off with a shorter fast e.g. begin fasting for 13 hours and build up to 16 hours. This gradual change gives your body time to adapt and tune into fasting, as well as the flexibility to dial it back when your body needs less stress. This type of fasting can be easily integrated into your schedule.


            How do you know where your ‘sweet spot’ is?


            When you're fasting, it is normal to feel hungry. However, you should not feel too low on energy, experience poor concentration, or anxiety, or crave sugary/carb foods. If you experience these before you break your fast, they are signs that you are fasting for too long. Remember, more is not necessarily better!


            What to eat when you are not fasting


            Often research doesn't focus on what to eat when you are not fasting, but this is a super important part of the process. Your breakfast is integral to maintaining a healthy blood sugar balance and sustainable energy when you're eating. Make sure your breakfast contains a mix of protein, complex carbs and fibre. Also, taking a multivitamin with Chromium can help your body regulate blood sugar.


            If you think your body would struggle to fast at all, first look at implementing a blood sugar diet as well as upping key nutrients such as vitamin D and magnesium. Once your body has a balanced approach to using and storing glucose, it will be better able to cope with starting a fast.