Most people relate intermittent fasting with easy weight loss. "Do this and you'll instantaneously lose weight", they said... However, not everything is black or white. In this article we discuss intermittent fasting to lose weight. What do you think, does it help you lose weight? We'll find out!
What’s Intermittent Fasting?
Intermittent fasting is an eating pattern that alternates between fasting and eating periods (source). Depending on the specific intermittent fasting, the fasting periods will be 12, 16, or even 24h. The fasting period will then follow to an eating window. Gather all the food there, and back to fasting.
There are different types of intermittent fasting: alternate-day, time restricted eating (TRE), or the 5:2 diet. In terms of severity and adherence, the TRE is the best and most use protool. It involves fasting every day for 12 hours or longer and eating in the remaining hours (study)
The roots of intermittent fasting reside on evolutionary nutrition and chronobiology. Since the agricultural revolution, our dietary patterns have changed tremendously. As before we weren't able to eat all day long, we are now used to eating every 3-4h.
Intermittent fasting relates to weight loss, but does it help you lose weight? Before getting into that, let's look at the principles of weight loss!
What Do You Need to Lose Weight?
We'll be clear here:
If you want to lose weight, you must be in a calorie deficit (study)
Calorie deficit is the only requirement to lose weight. Applying the 1st of Law of thermodynamics into our body, we can then get the formula of the calorie balance:
Calories In = Calories Out
Based on that formula, we can then have different scenarios. But this is the take away message: if you want to lose weight, you need to eat less calories than those you expend during the day
Does Intermitent Fasting Help You Lose Weight?
Now you know what intermittent fasting is, and what you need to lose weight. Let's put them together. Should you do intermittent fasting to lose weight?
Intermittent fasting can help you lose weight, but you won't lose weight simply by doing it. Only if you are in a calorie deficit you'll lose weight.
The evidence behind is still quite mixed, and we can' take anything as absolute truth. In this study, they saw how continuous dieting and intermittent fasting had the same outcomes in terms of weight loss.
In this other study, there was no difference between the control and intermitten fasting group. The evidence is still quite unconclusive, and we only know of the effects of intermittent fasting on the short term.
Intermittent Fasting Won’t Make You Lose Weight
Although intermittent fasting may help you, it won't make you lose weight by itself. Going to back to the CICO model ("Calories in = Calories out"), we need of a lower calorie intake than the calorie expenditure. If that's the case and we continue it over time, we will lose weight.
To understand this, let me show you something:
Both subjects are doing intermittent fasting... then both would lose weight right?
Not quite. While the first loses weight over time, the second one is maintaining or even putting some weight on!!
You can do intermittent fasting, that if your calorie deficit is not lower than your calorie expenditure, you won't lose weight.
If you do intermittent fasting with the aim of losing weight, do it good. Don't think you can eat anything from the fact you are only eating 8h a day. Since you are doing less meals, you can be a bit more flexible and do meals with more calories, but that doesn't mean you can eat anything.
Why Intermittent Fasting May Help you Lose Weight?
Intermittent fasting doesn't make you lose weight by itself. However, it is a very smart tool to use when trying to lose weight.
Intermittent Fasting Narrows Down the Eating Period
The main way by which intermittent fasting can help you lose weight is by narrowing down your eating window.
You’ll be doing less meals, which means that you’ll most likely end up eating less calories than you would if you were doing a normal diet. Less meals also means bigger meals, which could help you staying full and not suffering along the process (study)
Satiety has a big impact on the fate of your diet. If you are able to stay full in between meals, the likelihood of success will tremendously increase (study).
During intermittent fasting, you'll be doing less but bigger meals. Your satiety will be higher, and that will help you adhere to the diet.
You Won’t Continuously Think About Food
One of the main issues when trying to lose weight is the bad relation you can create with food. Food is always in your mind, and you have cravings all the time.
When doing intermittent fasting, your body adapts to the new meal timing. Your mind already knows when to eat, and when to not even think about food. That will help you adhering to the diet and achieve your weight loss.
More Control Over the Diet
If you consider doing intermittent fasting, it's because you care about diet to some extent. That already puts some odds in your favour to lose weight.
Since you have a defined eating window, your diet is more under control than when doing Ad Libitum diet (by feelings). Following this same fact, it is more likely that you get more aware of the food you eat, choosing healthier options.
Having more control over the diet will make it easier to choose the salad instead of the burguer next to it. Since you care more about your health, you'll be informed of the consequences of eating each of them, and your decision will be biased by this.
Cons of Doing Intermittent Fasting
Intermittent fasting may help you lose weight, but there are some other risks that come with it as well. As with everything, you'll have to assess both sides of the balance and conclude whether this is for you or not.
Intermittent Fasting May Not Fit Your Lifestyle
Intermittent fasting is not for everyone. Because of your schedule, or simply because you enjoy a nice breakfast first time in the morning, intermittent fasting may not be for you.
And that's totally okay. There are many other tools you can use to help you lose weight. Find the one that works for you and stick to it.
Intermittent Fasting May Be Too Restrictive
The problem with defined diets is the restriction it may create. If you are doing intermittent fasting, you may feel like you are not free to do or/and eat whatever you want at any time.
If you are craving a chocolate bar, or if your friend asks you to go out for breakfast during your fasting window... If you are not able to control that, you might have a hard time saying no to those plans.
May Create a Bad Relation with Food
Hunger accumualtes during the fasting period. Leptin levels start to decrease, and ghrelin peaks asking for food (study).
You finally enter into the eating window, run to the kitchen and assault the fridge. Eating everything you can, to the point you almost throw up.
Is that familiar to you? If it is, intermittent fasting is definitely not for you.
When doing intermittent fasting, you may enter into a cycle of binge-eating that will build a very toxic relation with food. To avoid that, you can alternate between fasting and normal days.
Intermittent fasting is an eating pattern that alternates between fasting and eating periods. Although it may help you lose weight, it doesn't make you lose weight by itself.
In this post we have seen why intermittent can fasting help you lose weight, and the potential risks of doing this diet. Make an assesment of both sides of the balance and conclude whether intermittent fasting is for you or not.