Intermittent fasting – and why it might just be the perfect weight-loss tool

Intermittent fasting, the weight-loss diet everyone’s been raving aboutSo many celebrities have tried and loved it – so much so that they’ve sworn by it ever since! Us Tummy girls love it too. And no wonder, with such compelling intermittent fasting benefits. But what’s all the fuss about, you may wonder?


Ok, first things first. 

What is intermittent fasting?

As intermittent fasting has held on as one of the go-to health,weight-loss and vitality methods for years, you may already know the answer to this one. But let’s do a quick recap – so what is it again?

Intermittent fasting is type of dietBut unlike regular diets, its not focused on WHAT to eat but WHEN to do it

That’s right, the latest research shows the timing is just as important. Why exactly is that so, you ask? Because biological processes including metabolism are closely connected to your circadian rhythm.

Okay, what is circadian rhythm againAnd why does it matter anyway?

Here’s the thing. 

Your body has an internal biological clock that regulates a number of physical and mental processes it goes through daily, also called circadian rhythm. 

Your circadian rhythmis influenced by external factors like light and dark or food, for instance. Based on the signals it gets, your brain activates specific hormones, regulates your metabolism and changes your body temperature to either keep you alert or prepare you for sleep.

Here’s how it works, ideally.

1. In the morning, in response to daylight and food,melatonin (your sleeping hormone) levels start to drop while the levels of serotonin(your mood stabiliserand cortisol and adrenaline(your stress hormones)start to riseYour metabolism starts to work fasterblood pressure starts to riseand alertness and energy levels increase, keeping you sharp during the main part of the day.

2. In the eveningyour digestive system and metabolism slow down while melatonin starts to rise and insulin sensitivity decreases, gradually preparing you for rest and regeneration.

During the nightyour body rests and regenerates, and your liver performs its daily clean-upBut only if you don’t eat too late at night.

When your metabolism is slowed, your body can’t make the most out of food the way it can during the day. Insulin is less effective at lowering blood sugar levels, your digestion takes longer, the half-digested food lingers in our gut for longer, and fat formation increases significantly.

Intermittent fasting can reinforce your circadian rhythm – and lead to weight loss

With time-restricted eating leading to relatively set meal schedulesintermittent fasting has been shown to help reinforce your circadian rhythm and boost weight loss.

People commonly choose to limit their eating window to 8-12 hours a day and fast for the restPopular intermittent fasting plans include:

    • the 16:8 diet, where people eat for 8 hours and fast for 16,
    • the 5:2 diet, where people eat normally5 days in a week and stay under 500 (women) to 600 (men) kcal a day 2 non-consecutive days in the week, and
    • the circadian rhythm diet, which is very similar to the 16:8 diet but allows an eating window of up to 12 hours, with breakfast and lunch being the larger meals of the day.

By following a set eating schedule every day, you encourage your body to go into fasting mode and burn fat reserves for energy, which can result in weight lossAs your digestive system can take its well-deserved break, your body can prioritise regeneration instead.

Ok, so what happens during fasting?

It all depends on the fasting period and your body composition. But generally speaking, the first signs of fasting show after 12-14 hours of not eating.

If you fast for16 hours(the 16:8 diet), changes are subtle but positive:

    • Your liver already stores less glucose and all nutrients from the bloodstream have now been sucked to places where they’re needed most.

    • Insulin levels decreased and intestines work on your last meal in peace.

    • Your stress hormone levels are low, you might also feel low on energy.

    • Your mind should be clear and focused.

Fasting for a longer period usually results in stronger effects

  • Due to lack of glucose, your body slowly goes into ketosis.
  • After that, its main source of energy becomes its own body fat.
  • Cells get more stress-resistant, the use of body fat is elevated and detoxification (autophagy) is at full power.

If you fast for days, things get more intenseAfter a few days of uneasiness, hunger and tiredness,however, you end up feeling alive, energised and muchleaner.

      • You find yourself peeing a lot and no longer looking puffy.
      • Due to constant visits to the bathroom, you need to drink more water.
      • Your ketosis is in beast mode. 

For optimal health and well-being, wdon’t suggest fasting for longer than a couple of days. In any case, we suggest you talk to your doctor or dietitian before kickstarting a new diet, especially a longer one.

Does intermittent fasting work

Intermittent fasting is a pretty well-researched diet plan. So what are some of the intermittent fasting benefits, you may wonder?

 A study by Mark P. Mattson PhD and Valter D. Longo showed intermittent fasting helps reduce obesity, hypertension, asthma and rheumatoid arthritis in people.

A study on rats showed that the levels of adiponectin – the skinny hormone – increase dramatically in response to fasting. When glucose levels in the liver decrease, insulin resistance is reduced, making your metabolism more efficient, decreasing fat formation and maximising fat burning. 

There is more research on humans needed, but rodents seem to react to intermittent fasting as if they were exercising regularly“[Their] responses to fasting are similar to those caused by regular aerobic exercise including increased insulin sensitivity and cellular stress resistance, reduced resting blood pressure and heart rate […].”

Experts on intermittent fasting say that combining intermittent fasting with a healthy diet – plant-based or Mediterranean, for instance – is an effective weight management approach.

Ok, so how to intermittent fast –where do you start?

We suggest you take some time to choose the intermittent fasting plan that suits your lifestyle best to make it as easy on yourself as possible

    • Think about what works for you – would you rather not eat breakfast or not snack after (an early) dinner? Then choose your plan accordingly.
    • When you know which part of the day you’ll be eating, start pushing towards it one hour at a time. If you decide to, say, skip breakfast and eat only between noon and 8 PM, start by gradually postponing your breakfast until you make it to noon.

Take time to nurture your new habits and drink lots of low-calorie fluids during your fasting periods

Need some help on the way?

We’ve been there. Time-restricted eating can be hardSous Tummy girls decided to make it easier for ourselves – and youWe’ve prepared a combination of products that comes super handy when you’re intermittent fasting, and especially when you’re only getting started.

    • Tummyccino is like your regular cup of coffee – just insanely better. Why? 

    Because aside from giving you a prolonged kick of energy, it also suppresses appetite, increases your metabolism and boosts weight loss – perfect for your fasting window. Drink it in the morning or early afternoon, whichever fits your preferred intermittent fasting plan best.

    • Shape Me Shake is a fortified high-protein and low-calorie protein shake that comes in a delicious hazelnut flavour. 

    The potent combination of slow- and fast-digesting protein, fibre, 11 vitamins and l-carnitine makes it a great snack for in-between meals. As a bonus, it will also help you feel energetic and build lean muscle easier if you combine it with exercise.

    • Slim Tummy Caps are powerful weight-loss capsules with Garcinia cambogia.

              They balance your sugar levels, boost fat-burning and prevent fat accumulation, helping you battle those cravings and lose weight more easily. Take 1 capsule about 30 minutes before two of your daily meals for best results.

    • Pure Me Tea is a functional herbal blend that boosts toxin elimination and supports your main detoxifying organs (your liver, kidney and intestines) for optimal night-time purification. 

    Treat yourself to a delicious steaming cup after your last meal of the day to tackle the fasting period more easily.

*To simplify the terminology and make the subject easier to understand, we use the concepts of intermittent fasting and time-restricted eating interchangeably. In scientific writing, intermittent fasting involves going without food for a minimum of 24 hours, while time-restricted eating involves going without food for a specific window of time within one day (as is the case with the 16:8 diet, for instance). )..


Almeneessier, A. S., Alzoghaibi, M., BaHammam, A. A., Ibrahim, M. G., Olaish, A. H., Nashwan, S. Z., & BaHammam, A. S. (2018). The effects of diurnal intermittent fasting on the wake-promoting neurotransmitter orexin-A. Annals of Thoracic Medicine, 13(1), 48–54.

Longo, Valter D., and Mark P. Mattson. “Fasting: Molecular Mechanisms and Clinical Applications.” Cell Metabolism, vol. 19, no. 2, 2014, pp. 181–192., doi:10.1016/j.cmet.2013.12.008

Mendoza, J., Drevet, K., Pévet, P., & Challet, E. (2008). Daily meal timing is not necessary for resetting the main circadian clock by calorie restriction. Journal of Neuroendocrinology, 20(2), 251–260.

Performance by Emily Manoogian, Pay Attention to Your Body's Master Clock, TEDxTalks, 22 Oct. 2018,

Van Laake, Linda W, et al. “The Circadian Clock in Cardiovascular Regulation and Disease: Lessons from the Nobel Prize in Physiology or Medicine 2017.” European Heart Journal, vol. 39, no. 24, 2017, pp. 2326–2329., doi:10.1093/eurheartj/ehx775.

Wan, Ruiqian, et al. “Cardioprotective Effect of Intermittent Fasting Is Associated with an Elevation of Adiponectin Levels in Rats.” The Journal of Nutritional Biochemistry, vol. 21, no. 5, 2010, pp. 413–417., doi:10.1016/j.jnutbio.2009.01.020.

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