Intermittent fasting for fat loss is a trend that comes and goes but for some is almost a dogma they swear it’s their magic trick to lose fat with virtually no changes in the lifestyle, like at all. I myself have heard with my very own ears the adagio “I stop eating at 8pm and I’ve NEVER felt better in my whole life”.
uhm, okay?
Being a bit of the skeptical type, when I hear these bold statements I always want to dig more to find out how true those can be and occasionally I try things myself to feel their magical effects. Let’s dive in.
What is Intermittent Fasting?
Intermittent fasting has been around for a long time, but it recently gained (again?) popularity alongside ketogenic diets and the concept of fat loss through ketosis. Let’s explore intermittent fasting for fat loss (also known as IF), and its potential benefits in this way, if it has any.
There are many patterns and timeframes involved with IF. The most common recommendation is to fast for at least 16 hours to then have an “eating window” of 8 hours. Some believe 12 hours is sufficient, but many seem to agree on 16 hours fasting for optimal results to start from.
Does it Have to Be Daily?
In principle you don’t necessarily need to fast every day.
Hardcore fasters might do it daily, with an 8-hour (or less) eating window and a 16-hour (or more) fasting window. However, the most common approach is skipping breakfast. But not everyone enjoys skipping breakfast so the beauty of IF is its adaptability to your schedule. If you want to do a 16-hour fast, have your 8-hour eating window whenever it works for you and your busy schedule.
There are harder patterns such as 20/4 where you fast for 20 hours and have all your meals during 4 hours or more extreme ones where you fast for 24 hours or more.
Probably the most nonsense and harmful type of fasting is the water fasting where people voluntarily refrain from having liquids for 24hours (or more). This is dangerous, do not do this, your body needs water.
Religion and Fasting
There are religious practices connected to fasting but for the sake of this article, I’m not going to say anything about this because it’s not relevant for nutrition for fat loss.
My Personal Experience with Intermittent Fasting
Intrigued by the potential of intermittent fasting for fat loss, I dove in headfirst to experience it for myself. However, right from the start, I had to adapt it to my lifestyle. As I love my breakfast, skipping it was absolutely unthinkable!
Working a 9-to-5, I chose to push back lunch a bit, have a mid-afternoon snack, and then begin my fasting window. This was to make sure I could enjoy breakfast around 7 am. This approach often meant a longer fasting window (around 20 hours) and a shorter eating window (around 4-5 hours).
From the beginning, I had embarked on a more challenging path and added occasional 29-hour fasts once a week on top of it.
To add even more challenge I had a really demanding schedule. Karate training, fights, and conditioning filled 4-5 evenings a week, lasting from 7 pm to 11 pm.
Irritability, Exhaustion: a Dose of Reality
The IF gurus online make it seem effortless, breezing through workdays on empty stomachs and conquering workouts like a walk in the park. Well, my reality was far from glamorous. The constant fatigue, hunger growls, and simmering anger were a constant battle on top of demanding customers, office drama, and brutal training sessions.
Sleep also suffered. Going to bed with a growling stomach wasn’t exactly conducive to restful nights. However, one surprising benefit emerged: I gradually acclimated to the constant hunger and learned to manage it. While the anger never fully dissipated, I became more aware of it, allowing me to control my reactions before tempers flared.
Weight Loss and Performance: Mixed feelings
Being already quite lean, weight loss wasn’t dramatic. However, I did shed some extra fat, undoubtedly due to the calorie deficit. My blood markers improved, but that likely correlated with weight loss, that included both fat and lean muscle mass – this being the undesirable mass to lose.
Furthermore, my training performance dropped. With less fuel in the tank, energy levels dipped and so did my performance.
The Decision to Stop
Ultimately, I decided to stop IF. It added unnecessary stress to my already demanding schedule. The constant hunger made food a persistent thought, and the fatigue was not helping either. Additionally, I wanted to build muscle that requires a calorie surplus, which wasn’t possible while being in a calorie deficit.
Challenges, Considerations and Science
Intermittent fasting can be challenging. Depending on your daily routine and energy needs, you might face physical or mental hurdles. Lower energy levels can lead to fatigue, irritability, or “hanger” (which is real!).
If you’re considering IF, start easy and on a less demanding day and maybe only once or twice a week to begin with.
Avoid the “all-or-nothing” mentality. Gradually ease into it by extending fasting periods until you find a comfortable interval. Don’t jump straight into a 20/4- hour fast like I did!
Intermittent Fasting and Fat Loss: The Truth
Can intermittent fasting help you lose fat?
Here’s where the debate heats up. IF can be a great tool to aid your fat loss journey, but there’s a big if. It doesn’t matter if you do fasting if you’re not in calorie deficit at the end of the day. If during your eating window you down ice cream and go over your daily calories….you will not lose fat.
There are also studies (here and here for example) that compare IF and regular caloric restriction that obtain very similar fat loss when the subjects had same daily calories.
With matched energy intakes, IF interventions produced similar beneficial effects for weight loss and chronic disease risk factors compared with DCR (daily caloric restriction).[Source]
That is to say, once again, that you can choose any way you want to be in calorie deficit to lose fat as long as you’re consistent.
Making Intermittent Fasting Work for You (if you really want to try it!)
One thing I got to give to IF is that, it can help you to structure your nutrition around a time interval and consequently could reduce random snacking because you make a “rule” for yourself.
If you’re calorie cycling (more about it here), intermittent fasting can help you reach that target by lowering your daily calorie intake and you might allow yourself a few more calories on some days to compensate for days with lower intake.
However don’t forget that using IF as an excuse to overeat during your feeding window won’t help making progress. Sure, you might have lower calorie intake on fasting days, but if the following days involve uncontrolled eating, it won’t be effective.
Be mindful – intermittent fasting is a tool, not a magic bullet. If you choose to do IF, maintain a healthy calorie deficit during your eating window and prioritize hitting your macros, especially protein.
This will help you preserve muscle mass while losing fat and curb hunger as protein keeps you fuller longer (more on protein here).
Certainly you DO NOT need any supplement (greens in powder, one for all) to aid your IF that influencers LOVE to sell you because “It MaKeS a HuGe DiFfErEnCe OMG”. They are not, in any way, better than having regular whole food.
Careful: Intermittent Fasting is Not a Fix
Intermittent fasting, or any form of extended fasting, should not be used to compensate for unhealthy eating habits. It’s not uncommon to hear about people doing long fasts and then overeating the following days. This creates a distorted relationship with food and can lead to bigger issues in the long run.
Fat loss should not be a race against time but a way for you to get sustainable results in the long term that work for you.
Stay strong!