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Introduction
Over the past 10 to 15 years, nothing has shaken the fitness industry as much as Intermittent Fasting, or IF for short. Fasting is not a new concept. However, fasting for health and weight loss purposes is a fairly new idea.
Intermittent fasting is restricting your eating window. By limiting your eating window, the idea is that you will naturally limit how much you eat which will automatically put you in a calorie deficit so that you lose weight.
There are a number of IF protocols which have different fasting and eating periods. Each protocols have their pro's and con's. We will discuss the different protocols. BUT First, history lesson time!
Let me take you back 10 to 15 years ago….
For most of modern fitness, the bodybuilding ideology of eating six meals a day, every 2-3 hours for health and weight loss was the norm. To say or think otherwise would mark you like Judas; betraying the gospel of nutritional advice.
Then came people like Martin Berkhan. When I first heard about IF and did some Googling, Martin Berkhan’s Lean Gain was at the top of the Google search list. Martin's idea was that if you spent 16 hours in a fasted state and spent 8 hours eating, you’ll get the same or even better results than your traditional “6 meals a day”. A lot of people stuck in their way argued, but the results Lean Gains produced were undeniable.
These days IF has grown into a popular, and viable method of eating for weight loss and health purposes. In this article, you will learn about different IF protocols and how it stacks up against the traditional calorie deficit when it comes to weight loss. You will also learn considerations and recommendations if you do want to try IF.
Introduction into IF
IF can be broken down into two broad categories: intra-weekly fasting and intra-day fasting.
Intra-weekly fasting
Intra-weekly fasting is fasting a few days during the week. Intra-weekly fasting can be further broken down into alternate-day fasting and twice-weekly fasting.
Alternate day fasting: Alternate day fasting is when you fast for 24 hours. This is then followed by 24 hours of eating. You alternate so every second day you are in a fasted state. All up, you will be fasting for roughly half the week. During the days that you eat, you can eat as much or as often as you want.
For example, let’s say you decide Monday is your fasting day. Tuesday you will eat normally, as little or as much as you want. Wednesday you fast, Thursday you eat normally and on and on it goes.
Twice-a-week fasting: Twice-a-week fasting involves two fasting days and five regular eating days per week. The fasting days can be consecutive or nonconsecutive. Again, you can eat as much or as little as you want on the non-fasted days.
For example, let’s say you want to fast during the day on Monday. You finish dinner at 8 pm on Sunday and will refrain from eating till 8 pm on Monday.
Intra-day fasting
Intra-day fasting is the most popular method of fasting. It involves fasting for a period between 14-20 hours and eating for 4-10 hours. Unlike weekly fasting, intra-day fasting has a shorter fasting window and you don’t need to avoid food for 24 hours. Intra-day fasting is also performed every day.
Intra-day fasting can be further broken into early time-restricted eating and delayed time-restricted eating.
Early Time Restricted Eating (eTRE)
Early time-restricted eating is when you place your eating window earlier in the day and start your fast late afternoon/early evening. The fasting window is normally between 14 to 20 hours long, and the feeding window is around 4 to 10 hours long.
For example, you decide to do a 16-hour fast, with an 8-hour eating window. You will eat from 7 am to 3 pm and fast until 7 am the next day.
Delayed Time Restricted Eating (dTRE)
Delayed time-restricted eating is the opposite of early time-restricted eating. You will generally wake up, go about your morning and refrain from eating till closer to midday. Once you’ve started eating, you’ll eat for around 8 to 10 hours (depending on the protocol you are following)
An example of dTRE is skipping breakfast and starting your eating window from 12 pm to 8 pm.
In both eTRE and dTRE you are free to eat as much or as little as possible.
What does this mean for me? Is Intermittent Fasting better than traditional calorie deficit?
Now that we’ve covered a little bit about intermittent fasting and its variation, the million-dollar question is; is IF more effective than traditional calorie deficit for weight loss?
Look... overall, the studies have shown IF, and all of its variants, have similar results to your traditional calorie deficit. Aragon and Schoenfield state that the underlying mechanism behind IF’s effectiveness is due to decreased energy intake and prevention of overeating.
Essentially, this same mechanism can be reached using a traditional calorie-restrictive diet. IF just has different guidelines that MAY or MAY NOT work for you! Pretty much the same destination, a different road type of deal.
IF is a tool to use to help you achieve your goal! The number 1 consideration you need to consider when deciding which nutrition protocol to use is whether you can STAY CONSISTENT with it or not!
Important considerations with IF
It is worth considering that studies comparing IF protocols and traditional calorie deficit showed a higher participant dropout rate in the IF group than in traditional calorie deficit. In a world where food is available 24/7, going without food, even for a few hours is hard. Plus, you have a life. You have things going on. Even if you are meticulous with your planning, sh*t can always come up which can put you off the plan.
For individuals with type 2 diabetes, IF may not be suitable for you due to the hypoglycaemic potential of IF.
A six-month study by Harvie et al. reported a significantly longer menstrual cycle in young, overweight women who performed twice-weekly fasting compared to a traditional calorie deficit.
Another big consideration is that IF has been linked to eating disorder tendencies. So, if you have a bad relationship with food, performing IF may not be the best option for you. You may find yourself eating your pantry clean after the fasting period is up. You know yourself better. If this sounds like behaviour you have, I would not recommend IF for you.
Side Story*: This eating disorder tendency happened to me in my younger, fitness days when I was experimenting with IF. At the time, between Sunday and Thursday, I would do a normal 16 hr fast, 8-hour feeding window. On a Friday I would eat all I can. By all I can eat I mean to the point where my stomach hurts and my wallet was empty from buying ice cream (yes I’m a sweet tooth). On Saturday I would fast all day and won’t eat again till Sunday morning.
I went a little extreme and stacked IF protocols together which is something I DON’T recommend. Yes, I lost weight but I also lost muscle mass and overall, it wasn’t a good experience for me. I share this story so that you can avoid my mistake.
Speaking of muscle mass loss…
IF and Muscle mass
We are going to finish this article by delving into the relationship between IF and muscle mass, or more accurately: loss of muscle mass.
Due to the nature of IF, research has shown that participants in the IF group, compared with participants in the traditional calorie deficit, lose more muscle mass. Both groups lost muscle mass, which is the case for most people when going into a calorie deficit, but IF showed a greater loss of muscle mass.
To counteract muscle loss when doing IF, you need to be performing resistance training and eating adequate protein. Your body needs a reason to maintain muscles. As they say, “use it or lose it”. If you decide to perform either the alternate day fasting or twice-a-week fasting protocols, please do your training on days you AREN’T fasting. You will perform and feel better.
Protein is the building block of muscles so you need to eat enough to help you maintain muscle mass. How much? Aragon and Schoenfield recommend a protein intake of 1.6g/kg.
An 80kg person needs at least 128g of protein to maintain muscle mass!
Conclusion and recommendations
IF has grown in popularity and is now seen as a viable way to lose weight and for fitness purposes.
Intermittent fasting can be effective when looking to lose fat and control weight. However, it isn't superior to traditional calorie deficit. IF is just another method that can lead you to the same results; fat loss.
The IF protocols can be modified to fit your individual needs. For example, the intra-week fasting protocols can be modified so you can eat 25% of total calories, instead of 0 calories on fasting days.
With the intra-daily fasting protocols, you can modify the fasting/eating window. Instead of 16/8 or 20/4, you can shorten it to 12/12 or whatever combination works best for you.
Ensure you eat enough protein to help with muscle mass retention, 1.6g/kg is the minimum you should aim for.
Perform resistance training! If you are doing intra-weekly IF, do your resistance training on days you AREN’T fasting.
I hope this helps, till next time this is Bryan from Bryan B Fitness, Cya!