When it comes to weight loss techniques, intermittent fasting is probably one of the most popular terms that I hear. For those of you who might also encounter this term quite frequently but aren’t entirely sure how it works, I want to go over what intermittent fasting is and how it’s supposed to work. In addition, if you’re considering whether you need to do intermittent fasting for weight loss, the truth is that you don’t necessarily have to, and I’ll explain that in more detail as well.
I know so many people who’ve implemented intermittent fasting at some point in their lives and who’ve tried to convince me to do the same when I was attempting to lose weight. Despite how common it seems to be, it hasn’t been shown to necessarily be more effective than other dieting methods, and it’s definitely not the best approach for everyone. Therefore, before you decide to hop on the trend, let’s take a deeper dive into this topic.
What Is Intermittent Fasting?
Firstly, let’s define intermittent fasting. Intermittent fasting is when you have specified periods during which you fast, or don’t ingest any calories. There are several popular types of intermittent fasting:
Time-restricted fasting is very common and involves limiting the amount of time in a day during which you’re allowed to eat. 16:8 is a common approach, meaning that every day, you give yourself an 8-hour window during which you can eat, but then fast for the other 16 hours of the day.
Alternate-day fasting involves alternating between days of eating normally and days of eating only 500-600 calories per day.
5:2 fasting is having five days a week to eat normally, but having two nonconsecutive days throughout the week during which you fast entirely.
What Does It Do?
There are many reported health benefits from intermittent fasting, but a major reason people do it is to lose weight.
In order for weight loss to occur, your body has to burn off fat. However, fat is your body’s last resort for energy, so it won’t turn to fat as long as you have food in your system. Normally, since you’d likely eat whenever you get hungry and are running low on food, your body is constantly being supplied with energy from what you eat and rarely has a chance to tap into its stored fat.
Instead, by going for extended periods without food, you increase the amount of time you run on an empty stomach and give your body more opportunities to use fat for fuel.
It’s also a way to physically restrict your calorie consumption. If you’re outside of your eating window, or fasting on that particular day, then even if you get hungry, you can’t eat anything, thereby reducing your calorie intake from what you would otherwise consume.
Is It Effective?
Now that you know how intermittent fasting is supposed to work, the question is does it?
The thing is, whether this approach is effective or not really doesn’t have much to do with when you choose to eat: fat loss is mostly determined by how much you eat.
In order to lose weight, you must consistently be in a calorie deficit, in which you ingest fewer calories than your body uses. If your body constantly expends more energy than it gets from food, then no matter when you eat, it’ll keep reaching a point of needing to use fat for additional energy.
Like I mentioned before, intermittent fasting can help you achieve a deficit by restricting when you can eat, but it doesn’t directly control how much you eat. With time-restricted fasting, if you manage to consume more calories than you burn in a day even in a limited window, you’re still going to gain weight. With alternate-day and 5:2 fasting, although you’ll achieve a deficit on your low-calorie or fasting days, if you’re eating at a surplus on your normal eating days, your weight will likely just fluctuate instead of going down.
Something else to consider is that if you want to lose fat but still preserve muscle mass, intermittent fasting might not be ideal. When it comes to muscle growth and maintenance, it’s optimal to have a steady supply of protein throughout the day. With intermittent fasting, since your body will go for long periods without any protein, you could potentially lose muscle mass more easily. Plus, if you can’t get enough protein during the limited periods when you’re able to eat, this will definitely result in muscle loss.
A Simpler Approach
By now, it should be pretty clear that when it comes to weight loss, your main concern should be the number of calories you consume in a day.
You can try intermittent fasting if it suits your lifestyle and you think it might force you to limit your calorie intake; however, if you’re just focusing on when you’re eating without monitoring what you’re eating and how much you’re eating, you’ll find it hard to achieve weight loss no matter how strictly you stick to your fasting approach.
On the other hand, if you’re able to maintain a daily calorie deficit without needing to implement rules that restrict your eating window, you can eat consistently throughout the day, every day, and still lose weight very effectively. You can learn more about how to properly do this in my post Bulking and Cutting Explained.
Focus on What Really Matters
Intermittent fasting isn’t a miracle approach to fat loss. It can facilitate the process in some cases, but if you’re hoping that it’ll simply replace the need to watch your diet, you’re unfortunately going to be disappointed.
In the end, intermittent fasting itself doesn’t cause weight loss; it’s merely a system that can help you achieve the circumstances needed for it to happen, that being eating fewer calories than you consume in a day and allowing your body to tap into stored fat for energy.
It might work, it might not, but above all, it isn’t really necessary.
