• Fasting - Part 2. Practical Applications

    How to incorporate the practice of fasting in our everyday life


         As we saw in the first part , fasting is the voluntary avoidance of food for health, spiritual, or other reasons. It’s done by someone who is not underweight and has enough stored body fat to live off. When done correctly, fasting should not cause suffering, and certainly never death. Food is easily available, but you choose not to eat it. This can be for any period of time, from a few hours up to a few days or – with medical supervision – even a week or more. You may begin a fast at any time of your choosing, and you may end a fast at will too.

    So, in theory,  anytime we are not eating ,we are intermittently fasting. But let’s dive into the science behind it.

        Intermittent fasting (IF) covers a broad class of dietary interventions that alternate periods of eating and extended fasting on recurring basis. IF interventions can include periodic 24-hour fasts, intermittent energy restriction (e.g., the 5:2 protocol), and time-restricted eating (TRE). Our bodies need a 24 hour continual source of energy just for the basic metabolic housekeeping – keeping the heart pumping blood, liver and kidney functions, the lungs sucking air, brain function etc. Since we do not eat food all the time, we have a system of storing food energy (in the liver and as body fat) for times where we are not eating, like when we are sleeping for example.  At moments like these , our body needs to pull some of the food energy we’ve stored away to keep our vital organs running. This is the reason we do not die in our sleep every single night.
       So, it becomes obvious that IF is not something unusual but a part of everyday, normal life. Yet somehow we have missed its power and overlooked its therapeutic potential. For example, you may be already intermittently fasting every day , between the dinner and the breakfast of the next day, a period that for most people is approximately 10 hours. Although the main benefits of IF start to appear after 12 hours of not ingesting any food, the 10 hours you stayed without feeding your self still count as IF. Just consider the term “breakfast.” It refers to the meal that breaks your fast – which is done daily in the morning. In that sense, even the English language implicitly acknowledges that fasting should be considered a part of everyday life.
        As we saw in the first part of this series,  at its very core, fasting simply allows the body to use its stored sources of energy – blood sugar and body fat. This is an entirely normal process and humans have evolved these storage forms of food energy precisely so that we can fast for hours or days without detrimental health consequences. Blood sugar and body fat is merely stored food energy ready to fuel the body when food is not available. By fasting, we are lowering blood sugar and body fat by using them precisely for the reason we store them. So, if we need to restore balance in our dietary patterns , if we need to achieve metabolic flexibility or if we need to lose weight, we may simply need to increase the amount of time spent burning food energy.

    That’s intermittent fasting.

    Intermittent fasting benefits

    IF’s most obvious benefit is weight loss. However, there are many potential benefits beyond this, some of which have been known since ancient times.  The fasting periods were often called ‘cleanses,’ ‘detoxifications’ or ‘purifications,’ but the idea is similar – to abstain from eating food for a certain period of time. People believed that this period of abstinence from food would clear their systems of toxins and rejuvenate them. Since we talked excessively about the benefits of fasting in general in the first part of this series, in this post i will just mention the most important benefits of IF reported through scientific research :

    • Weight and body fat loss - improved body composition.
    • Lowered blood insulin and sugar levels
    • Lowered blood insulin and glucose levels - Reversal of type 2 diabetes
    • Reduced hemoglobin A1c (A1c) levels
    • Improved mental clarity and concentration
    • Increased energy
    • Increased growth hormone, at least in the short term
    • Improved blood cholesterol profile
    • Increased longevity
    • Activated cellular cleansing by stimulating autophagy
    • Reduction of inflammation


    How can we apply in our everyday life the practice of IF?  Here, i am presenting some of the most important protocols.



        1.  Time-restricted eating (12:12 fasting, 14:10 - 16:8 fasting, 18:6 fasting, and 20:4 fasting)

        While IF, is a term used to describe a lot of different protocols, it’s most often used to describe something called Time Restricted Eating (TRE)—meaning, restricting the period of time you eat to a set number of hours each day. Time restricted eating, also called time restricted feeding (TRF) in research settings, typically consists of confining all your eating to a 12-hour, 10-hour, 8-hour, 6-hour, or 4-hour window, and fasting the remainder of the day. Lets see them analytically :

    • 12-hour fasting

    Many experts view a 12-hour eating/12-hour fasting window (think: eating breakfast at 8 a.m. and wrapping up dinner by 8 p.m.) as a great, safe place to start for anyone. It shouldn’t be that difficult , since one can fit the 8 hours of sleep in the 12 hour fasting window, therefore the challenge here is to remain without food for 4 more hours.  Piece of cake !

    • 14:10 and 16:8 fasting

    Some of the most popular versions of TRE are the 14:10 or 16:8 fasting plans, which consist of a daily 14-hour and 16-hour fast while confining your eating to an 10-hour and 8-hour window respectively. If you can't live without breakfast, slot your food earlier in the day (8 a.m. to 6 pm or 4 p.m.). If you prefer an early dinner, eat in the middle of the day (11 a.m. to 9 pm or 7 p.m.). If you're someone who regularly goes out with friends for late dinners, schedule your eating hours later in the day (1 pm to 11pm or 9 pm).

    • 18:6 fasting

    Also popular, but a bit more intense, is the 18:6 fasting plan, which is a daily 18-hour fast where you confined your eating to a 6-hour window. If your goal is weight loss and you’ve experienced a plateau on a 16:8 plan, this is the logical next step. While more research is needed, an 18:6 fast likely helps your body burn stored carbohydrates (glycogen) faster so you can start burning fat (in the form of ketones) for fuel, and some believe it may be enough to activate autophagy—a cellular clean-up process that’s associated with longevity.

    • 20:4 fasting

    The most restrictive of the popular TRE regimens is the 20:4 fast (sometimes called the “warrior diet”), which is a daily 20-hour fast where you confined your eating to a 4-hour window. This essentially breaks down to one meal a day and is not for beginners—you need to work your way up. Compared to a 16:8 or 18:6 fast, it’s speculated that you will burn more fat, lose more weight, and experience greater autophagy on a 20:4 diet, since the fasting hours last for almost all day.


           2.  Alternate-day fasting (36 hour fast)

          Also under the umbrella of intermittent fasting is alternate-day fasting (ADF). ADF is just how it sounds: You only eat every other day. So, practically,  you fast for 36 hours on a recurring basis. You finish dinner on day 1 at 7 pm for instance, and you would skip all meals on day 2, and not eat again until breakfast at 7 am on day 3. So that is a total of 36 hours of fasting followed by an 12-hour eating window. While some purists only consume water, herbal tea, and moderate amounts of black coffee on fasting days, others employ the 25 percent rule. In this version, you consume 25 percent of your normal caloric intake on fast days. This protocol has shown really good results for weight loss and reducing inflammation and while many clinics often recommend 36-hours fasts 2-3 times per week for reversing type 2 diabetes, alternate-day fasting is a more extreme approach to IF that may be hard to sustain over the long term. For obvious reasons, is not for beginners, and it should be reserved for specific medical cases.


        3.   5:2 plan

        A slightly easier variation of ADF, the 5:2 plan allows you to eat normally for five days every week while eating only 500 to 600 calories on the other two days. You can choose whichever two days of the week you prefer, as long as there is at least one non-fasting day in between them. One common way of planning the week on this protocol , is to fast on Mondays and Thursdays, with two or three small meals, then eat normally for the rest of the week. It’s important to emphasize that eating “normally” does not mean you can eat anything. If you binge on junk food, then you probably won’t lose any weight, and you may even gain weight.


    Where to place your TRE window?

         The ideal placement of your eating and fasting window will likely depend on a number of factors—work schedule, social obligations, fitness routine, and simply what feels best for your body—but a growing body of research seems to suggest that an earlier eating window may be better. A small but rigorously controlled randomised crossover study from 2019 found that when participants ate between 8 a.m. and 2 p.m., they fared much better than when they ate the same three meals on an 2 p.m. to 8 p.m. schedule.  Moreover , they had lower blood glucose levels during the day and overnight, lower insulin levels, and an ideal cortisol pattern (with levels higher in the morning and lower at night)—all of which suggests an improvement in circadian rhythm. More surprisingly, though, was that after just four days, this earlier eating schedule increased the expression of the SIRT1 gene (associated with longevity and healthy aging) and the LC3A gene (a biomarker of autophagy).



    How do you manage hunger?

       The million dollar question! “If i am hungry in only 3 hours after eating , how will i be able to fast for many more hours?” … Hunger is not so simple as your stomach being ’empty’. Hunger is, in fact, a highly susceptible state with a complex hormonal regulation at play. In essence, there are two major components to hunger: The unconditioned biological stimuli – that is, the part that will normally stimulate hunger naturally (smells, sights, and tastes of food) and the conditioned stimuli (learned – movie, lecture, morning etc). These conditioned responses can be very powerful and cause great hunger. If for example we consistently eat breakfast every single morning at 7:00am, lunch at 12:00 and dinner at 6:00pm, then the time of the day itself becomes a conditioned stimulus for eating. Even if we ate a huge meal at dinner the night before, and would not otherwise be hungry in the morning, we may become ‘hungry’ because it is 7:00am. The Conditioned Stimulus (time of 7:00) causes the Conditioned Response (hunger). How to combat this? Well, intermittent fasting offers a unique solution. By skipping meals and varying the intervals that we eat, we can break our current habit of feeding 3 times a day. We no longer have a conditioned response of hunger every 3-5 hours.
        And what about the hunger we feel by the unconditioned biological stimuli during our day? The most important thing to realise is, that this type of hunger, usually passes like a wave. It comes and it goes. That is, we may not be hungry one second, but after smelling a steak and hearing the sizzle, we may become quite ravenous. And then, we may engage in an activity and we forget after some minutes completely the steak and our hunger .  Many people worry that hunger during IF will continue to build up until it is intolerable, but this does not normally happen. Approximately 3-6 hours after we eat a meal, we start to feel hunger pangs and may become slightly cranky. But if we simply ignore it and drink a cup of tea or coffee, or we keep ourselves busy with activities , it will often pass.



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