What is it that everyone is talking about lately?… Intermittent fasting is not just a trending topic, and precisely because of this, it requires our attention. Because when a topic is trending, many people do it but might don’t know exactly why.

I will share here not only my experience with intermittent fasting and what I have learned while doing it, but also some info that I have collected over the years, researching on my favorite topic … you know, healthy living 🙂 and IF specifically.

What is intermittent fasting?

I’ll start by explaining it in a few words: it is about reducing the period in which you eat from day to day. That is, if you previously made all your meals within 12 hours, for example, from 8AM to 8PM, now, you are going to reduce that time frame to 8, 6 or 4 hours.

In my case, for example, I’ve been fasting for at least 13 hours daily for along time. Why? Because it is proven that this is the minimum time required by the body to regenerate and optimise health. And it can actually help manage jet lag symptoms in people who travel between time zones or work night shifts. The first time I heard about this concept was from a scientist named Emily Manoogian. I leave you this podcast here below where she talks about chronobiology and circadian rhythms:

Regarding intermittent fasting, after doing some research (and wanting to save time), I extended my fasting hours from 13-14 to 16. In fact, I was already doing it unintentionally, on weekends when I went to the gym and I came home around 11AM to brunch; then I’d had another big meal in the afternoon and didn’t eat any more until the next day… this because of practicality and because these two meals were always nutritious and filling enough.

Understanding the benefits of intermittent fasting even better, I then decided to adopt it as a lifestyle, and now I do a total of 18 hours, almost every day. I say almost because there are days when I make exceptions, but not because I am starving as some of you may be thinking … I make exceptions for reasons of agenda, friends or family meetings. On most days when neither of these is the case, my fast is 18 hours, like this: I have one last meal of the day between 4:30 and 5:30 PM, and the next day I have breakfast at 11:30 AM – 12:30 PM.

What for?

The benefits of intermittent fasting are many! Here I am going to list some, explained by health professionals experts: Dr. Sebastián La Rosa (from Argentina), Dr. Carlos Jaramillo (from Colombia) and Dr. Michael Greger, MD (from the United States).

Main benefits of IF:

  • It helps to lose weight because it promotes the reduction of body fat.
  • If you do strength training, it promotes the increase of lean mass, that is, muscle gain.
  • Stabilise your energy levels, because it allows the expenditure of energy from fat.

Quoting Dr. Michael Greger, one of my most trusted sources of information:

“Fasting has been called ‘the next fad diet’ but it has a long history through various spiritual traditions, practiced by Moses, Jesus, Muhammad and Buddha. In 1732, a prominent physician wrote: ‘He who eats until he is sick must fast until he recovers’.”

Have you ever wondered why we lose our appetite when we get sick?

The fasting that we now call “intermittent” is really something that probably our ancestors already did by nature, due to the availability of food, or the way they had to get it. As well as going to sleep at dusk and getting up at dawn. It was the environment in which they lived what fostered their habits, just as it is now. It is precisely for this reason that we must take care of our environment. In every way.

But going back to fasting, this is nothing new.

“Case studies on the treatment of obesity by fasting date back more than a century in the medical literature.”

And speaking of diets… I keep quoting Dr. Greger:

“The reason diets don’t work almost by definition is that people go on them and then off them. Permanent weight loss is only achieved through a permanent lifestyle change.”

As for fasting …

“The break from food can give some a chance to pause and reflect on the role food plays in their lives, not just the power it has over them, but the power they have over it.”

I am amazed at how easily people adopt intermittent fasting, even some who have experienced eating disorders. I know specific and very close cases in which once people begin to do this type of fasting, they adapt and experience its benefits from the first days. This keeps me thinking that it makes a lot of sense, and that fasting is in our nature.

“Fasting for a day can make people moody, irritable and distracted, but within days of fasting, many report feeling clear, calm and alert, even euphoric. This may be due in part to the significant rise in endorphins that accompanies fasting. Improved mood during fasting is believed to perhaps represent an adaptive survival mechanism to motivate the search for food. This positive outlook for the future can facilitate the behavior change necessary to secure some of the benefits of weight loss.”

Intermittent fasting makes us happier! However, it is super important that people learn how to eat, rather than learning how to do intermittent fasting, or adopt it as a lifestyle.

It is precisely at this point where I’ve had the opportunity to accompany these cases mentioned above, and I am glad to see how these people have understood the importance of the quality of food they eat when not fasting. You must be really feeding yourself; nourishing your body, giving it what it needs. Because just as we need fasting, we also need a balanced diet. Not light, but nutritious.

“Fasting only works [as a weight loss strategy] in the long term, if it can act as a boost to a healthier diet.”

Please bear in mind that I am talking here about INTERMITTENT FAST: 14, 16, 18 and up to 20 hours; and not longer periods of fasting, or water-only fasts for days. These types of fasting exist, and are done as treatments in specific cases, but they must always be consulted, supervised and accompanied by supplementation of vitamins and minerals. The consequences of long periods of unsupervised fasting can be very serious.

How is it done?

The hours in which you give fuel to your body, that is, food, are reduced. But not just any kind of food! It is not “like whatever because I am fasting”, no! … I’ll repeat this quote on purpose:

“Fasting only works [as a strategy for weight loss, mass gain, and treating some diseases] in the long term, if it can act as a boost to healthier eating.”

If your last meal of the day is at 9:00 PM, the next day you will eat your first meal at 1:00 PM – count 8 hours back. To further reduce this “window” of time, then count 6 or 4 hours, that is, break the fast at 3:00 PM, or at 5:00 PM. Before your first meal you should drink enough water and you can drink coffee, tea or herbal beverages without added ingredients.

I prefer to do everything earlier. As I said, my dinner is no later than 6PM and my breakfast is between 11AM and 12. It is preferable, because of something called our circadian clock, the body needs more calories earlier in the day, and processes them better. Eventually I want to get to do breakfast and dinner even earlier, but right now it works well for me that way, because of my schedule and other activities of the day. And I invite you to do the same, adjust your new habits to your schedule.

What happens in the body when we fast?

  • In approximately 12 hours, the glycogen stores in the liver and muscles are consumed (energy that comes from carbohydrates and that we use mainly for mechanical movements), from here your body uses fat for energy. For this reason, it is recommended fasting to be a minimum of 13 to 14 hours.
  • This energy is more efficient, it benefits athletes but also anyone, because it is constant, it does not go in glucose peaks (as when we snack).
  • The smaller the window (or the longer the fasting time), the more fat you use for energy. Reducing the percentage of fat in the body is not only a physical benefit, it is to prevent your body from accumulating fat and avoid cardiovascular problems, chronic inflammation, obesity, high cholesterol, etc.
  • Concentration and attention span are also improved. And cravings decrease throughout the days.
  • In longer fasts, a process called gluconeogenesis is generated, and this stimulates the growth hormone.
  • Cell regeneration is optimised.

When we are trying to lose weight, according to Dr. Carlos Jaramillo:

“… Intermittent fasting does not work due to a calorie deficit, it works because the work of insulin in the blood is regulated. And the burning of fat as energy in the body is optimised.”

But taking into account the quality of calories we consume.

Not only can we lose weight through intermittent fasting, we can also:

  • Control insulin
  • Manage pre-diabetes and diabetes
  • Promote the production of the growth hormone
  • Regulate levels of cortisol – the stress hormone
  • Leveling triglyceride levels
  • Reduce cravings, increase energy
  • Control metabolism
  • Lose fat

As I mentioned before thinking about fasting, it is VERY important to learn how to eat well. And just as important as eating well is maintaining the necessary hydration. While you are fasting, exercising, and at all times, drink enough water. Water is life, literally.

And something you should know and DO NOT FORGET is that, to quote Dr. Jaramillo again:

“… all ‘zero calorie’ artificial sweeteners stimulate insulin. Sweeteners increase anxiety and contribute to weight gain. And all artificial drinks, even if they are zero calories (except water, coffee or tea), break the fast. “

Intermittent fasting is not a diet. It should become your lifestyle and what is recommended to eat after fasting is what everyone should eat. Varied food, from the land, nutritious and healthy.

Intermittent fasting only provides benefits and does not pose any health risk. There are some cases in which it is contraindicated and I’ll list them here below:


  • People with gastric ulcers.
  • Being pregnant and breastfeeding (this because of lack of evidence, not because it “hurts the baby” – it just isn’t proven).
  • Hormonal disorders (proven, not only if you think you have hormonal disorders) and people with extreme fatigue problems or uncontrolled thyroid problems.
  • Advanced situation of liver failure or kidney failure.
  • Porphyria – a group of metabolic diseases, which is a very rare condition.

If none of the above is your case, any message that your mind is sending against intermittent fasting may be resistance to a new concept, analyze it and think about it…. Try it 3 days and tell me how it goes! 🙂

To do intermittent fasting you must take into account the following:

  1. Learn to eat well, know which are the foods that optimise your health.
  2. Learn to eat 2 or 3 times a day.
  3. The feeling of hunger (which is sometimes anxiety) occurs because you continue to produce insulin, as the fast progresses, hunger is significantly reduced.
  4. All artificial sweeteners and everything that is “zero calories” increases anxiety and contributes to weight gain.
  5. It is important to maintain good hydration during the fast, and always.

FAQs – Frequently Asked Questions 🙂

Can you exercise while fasting?

Yes. Be it cardio, strength or flexibility, what you do is depleting glucose stores and start using fat for energy, you burn fat more efficiently and it is energy of better quality.

Should a cleanse be done before or after the fast?

No. Our body has its own cleaning systems. The idea is that we maintain a clean diet and thus our body remains healthy.

What is the main purpose of intermittent fasting?

To enjoy all the benefits it has to offer! Not only is it a strategy to lose fat, it helps us to be more focused and prevent diseases.

Can I eat anything when I’m not fasting?

No. It is very important that you eat well. That your meals are balanced and nutritious. The mere fact of fasting is not what brings the benefits, it is the complement between fasting and how well you eat.

Can I add spices to tea or coffee while fasting?

Spices like cinnamon, pepper, turmeric, yes. Fruits, sugar, milk or oils, NO. These break the fast because they have calories.

Coffee and tea have calories?

No. Or not enough to generate digestion, a black coffee has less than 5 calories. You spend more on making it and drinking it.


1. If you want to start intermittent fasting, do it from 12 hours first and continue increasing one hour every day.

2. Make your last meal of the day early (we don’t need a lot of energy to end the day or go to sleep) – assuming your life takes place primarily during the day.

3. Finally, the most important thing is the quality of the food you eat during non-fasting hours.


Author: Carolina

I used to be a Digital Project Manager with a passion for healthy food and fitness. Now I’m a full-time healthy lifestyle advocate, on a mission to spread the word about the best medicine: healthy life habits. I am a certified Health & Nutrition Life Coach, Les Mills BODYPUMP™ Instructor, and PADI Scuba Diver; I am a sociable and positive individual, I speak three languages and this has allowed me to get to know and understand several cultures. I love learning, and I have achieved most of what I aimed in life. I value justice, empowerment, friendships and a sense of community. I don’t like enclosure, artificial things, nor melon. I enjoy life, and I take care of the planet.

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