Intermittent Fasting for Weight Loss A Good Plan or Another Fad Diet

Our nutrition expert demystifies what intermittent fasting is, and outlines the questions to ask yourself before trying it.


The first time I heard about intermittent fasting was on Saint-Jean-Baptiste Day in 2016. I was heading to the fireworks when an old friend recognized me in the darkness:

  • Hey Nico, you’ve become a nutritionist, haven’t you? What do you think about intermittent fasting?
  • The what?
  • Intermittent fasting! Not eating anything for 16 hours every day!
  • So… not eating lunch?
  • No, it’s more complex than that. It makes your brain sharp and you lose weight and everything.
  • Hmm. Hey, look, a firework in the shape of a smiling man!

After skillfully extricating myself from the conversation to avoid getting involved in a subject I had no grasp of, I went back home and asked for information.

What is intermittent fasting?

Fasting is the act of depriving yourself of food and fluids. Intermittent fasting involves designating periods when you are too fast, and other periods when you are allowed to eat and drink. I describe in more detail how it works, what the risks are, and what the results are here.

Some fast for 16 hours every day, others for 24 hours a few times a week, and others give themselves access for 1 or 2 days to only 25% of what they eat the rest of the week. In short, there are several types.

Of course, there is no fasting police, but like a racehorse, we put on mental blinders and stay in our lane by implementing this new eating routine. At the finish line? It depends on the person, but most are aiming for weight loss.

The real question that comes up all the time is: does intermittent fasting work for weight loss? To better answer, I have two avenues of thought for you:

1. On the one hand, yes fasting can help you lose weight.

The easy answer is yes. In the majority of studies on the subject, intermittent fasting leads to weight loss. Based on the participants recruited, one review of studies reported an average weight loss of 7 kg throughout 3 to 12 months.

2. On the other hand, the effect of fasting on weight must be qualified

Nutrition is complicated, it’s full of gray areas! That’s why we need a nuanced answer.

First, it’s important to maintain your relationship with food to avoid developing an eating disorder. At the end of the day, you’re worth a lot more than your number on the scale. And I’m not saying this to give you a cheap pep talk, it’s just a fact.

What is complex is that in the short term, following a diet is perceived positively. According to a report by ANSES in France, “losing weight gives you energy” (obviously a French expression!) and “affects mood, self-esteem and self-confidence.”

In this sense, a researcher named Bacon (yes!) conducted a very interesting study in 2005 to analyze the mental health of a group of obese women (according to BMI criteria). For 2 years, half had to target improving their health without aiming for weight loss, while the other half had to target weight loss. After 1 year, the women in both groups had better self-esteem and were less depressed.

After 2 years of follow-up, only women who were aiming for health improvement without weight loss had improved self-esteem. Women aiming for weight loss had worse self-esteem than before they even started the study.

Every diet has its honeymoon period at the beginning, but dissatisfaction catches up with us when we realize that the restrictions are not sustainable in the long term, or that they no longer bring the expected results.

Another thing to consider: Intermittent fasting leads to weight loss, but not necessarily fat loss. Often, restrictive diets decrease muscle mass. And muscle mass greatly influences our basal metabolic rate (i.e., the energy our body expends just to keep us alive). For this reason, a decrease in muscle can contribute to greater weight gain when we get tired of fasting and start eating normally again.

Finally, it’s not all negative (I told you, nutrition is full of gray areas!) Some studies report that intermittent fasting when compared to simply eating less daily, is easier to follow, reduces the risk of malnutrition, and leads to similar results.

What I propose

Intermittent fasting does not have to be a restrictive experience in itself. I encourage those who want to try it to first think about their motivations.

If you’re going to give it a try: do it! You may notice that you sleep better by eating less late at night or that a light workout upon waking seems easier. Stay tuned to the signals from your body and mind to better assess whether this practice is right for you.

If the goal is weight loss, think about what is behind that desire:

  • What will weight loss bring you?
  • How could your lifestyle habits be improved without affecting your weight?

And the most important question, borrowed from nutritionist Karine Gravel with her permission, is:

Clarification: if you want to lose weight, your motivations are 100% valid. We have always associated health with weight (wrongly, but that’s a whole other subject!) But, I assure you that it is possible to take care of your body and your mind without aiming for the number on the scale. Who knows, maybe the famous number will move, but one thing is certain: working on goals that you can control is a much healthier approach.

Things to remember about intermittent fasting

With the right information, intermittent fasting can be approached as an interesting experiment to try. If you do it with respect for your body and mind, you can learn about yourself! The mistake not to make, however, is to choose intermittent fasting to lose weight. It will probably work in the short term, but in the long term, it risks worsening your relationship with food or lowering your self-esteem.


Please enter your comment!
Please enter your name here

Must Read