From Intermittent to Circadian… Different types of fasts, their benefits and drawbacks

For quite a while now, fitness enthusiasts have been raving about different types of fasts. Each comes with its own set of advantages and disadvantages.

Intermittent fasting: The term may have been coined recently, but this pattern of eating exists since ancestral times. During the old days, the last meal of the day used to be just before sunset because of the lack of electricity, and the first meal was right after sunrise. This automatically gave the human body fasting of 14-16 hours. So, intermittent fasting was, almost, like a way of life for our ancestors. In intermittent fasting, one stops eating after a particular time and moves to only plain water for a specific period, and then slowly resumes eating. The phase in which one fasts is called the elimination phase and the phase in which one feeds is called the building phase.

Intermittent fasting benefits our body beyond weight loss. It helps our digestive system take a complete break which is not only healing to the digestive system but the entire body. It boosts our immunity, calms down inflammation and is termed a natural pain killer that works amazingly well for any arthritic pains. It helps in detoxification. It is also anti-aging and boosts skin and hair health.

Who shouldn’t do it?

While the benefits of intermittent fasting are powerful and are recorded in medical and scientific journals, it does not suit everyone. Below are some cases where intermittent fasting must be avoided or practised only under medical supervision.


  • First, set the right intention when you fast. The intention is everything. Do not fast with the intention to only lose weight. Fast because it helps you become disciplined and align with nature. Fasting is not a shortcut to losing weight and it shouldn’t blind you from making lifestyle changes.

  • During intermittent fasting, drink only plain water in the fasting phase. No tea, coffee, or infused water as anything other than water. If one wants to adopt fasting, one must do it the right way.

  • Thirdly, set the timings, eating patterns, and hours of fasting according to what suits you and your lifestyle. Don’t fast for 16 hours just because everyone else is doing it. If you are a beginner, start slow and build up gradually.

  • In the building phase, make sure you really eat well. Don’t diet in the building phase, else you will only cripple your metabolism. Get your macros and micros, vitamins, and minerals. Fasting is not starvation. In fact, if one doesn’t nourish well, they might end up looking undernourished, weak, and haggard.


Wet fasting: Wet fasting means drinking only plain water during the fasting window and resuming eating as usual when the fasting period is over. A lot of people bring in juices, tea, coffee, infused water, and other beverages in the name of wet fasting. However, it is important to understand that putting anything other than water, in your system will make your digestive system work instead of putting it to rest. Therefore, remember to drink only water.

Dry fasting: Dry fasting is a step ahead of intermittent fasting. Here, one does not consume even water during the fasting period. This is powerful because it gives a complete break to our digestive system, and redirects all the energy towards healing, recovering, cleansing, repairing and other vital functions. Dry fasting can also be eased into wet fasting, which is called integrated fasting.

The mechanism of dry fasting is simple. Our digestive system is the largest consumer of our body’s energy. It utilises almost 80% of the energy into digestion, absorption, and assimilation, leading 20% of the energy towards — healing, repair, recovery, growth, rejuvenation, detoxification, immune system. Too much eating, eating at the wrong timings, or overeating can direct all energy towards digesting, leaving little or no energy for repair and recovery. When one fasts the body’s energy is redirected towards healing, repair, rejuvenation, boosting the immune system, stem cell regeneration, hormonal imbalance, etc.

Dry fasting activates our body’s intelligence to do what it needs to do. Due to the absence of water, dry fasting helps reduce inflammation.

Fasting is healthy if it suits you, your health and makes you feel better. Most of us need to let go of the idea that 16:8 fasting is good for us. What if your body doesn’t need 16 hours of fasting, and can operate at its optimum with just 12 hours of fasting? All of us are unique bio individuals, so fasting must be as personalised as nutrition or exercise. The ‘one shoe fits all’ approach will not work here as well.

Circadian fasting: By far, one of the most natural ways of fasting that have worked for most people who have followed it with discipline and consistency is circadian fasting, which aligns the fasting and feeding window with the circadian rhythm (sunset and sunrise). This type of fasting results in a natural 12-hour fast. We utilise the power of circadian rhythm, which has a deep connection with digestion, detoxification, repair, and recovery.

(The writer is a Holistic Nutrition and Lifestyle — Integrative and Lifestyle Medicine, Founder of YouCare — All about YOU by Luke Coutinho)

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Published on: Sunday, May 01, 2022, 01:00 PM IST