What is Intermittent Fasting?
Intermittent Fasting (IF) is the process of alternating periods of not eating (i.e. fasting) with a particular window of time in which you are allowed to eat. The eating window varies in time; some people choose to have 10 hours, others only have 6 hours. However, as a general rule of thumb, the eating period lasts 8 hours.
While a lot of people dismiss IF as a fad diet, it’s important to note that everyone fasts, whether you realise it or not. The simple definition of fasting is “not eating". Therefore, anytime you’re not eating, you’re fasting.
The difference is most people's window of fasting isn't constant, so rather than fasting intermittently, they're fasting irregularly. An exception to this for the majority of people is sleep. When you’re asleep, you’re in a fasted state; thus we have a consistent fast period of 6-8 hours each day, until the morning, in which people will have breakfast. This is actually why our morning meal is known as “breakfast”, as you are breaking your overnight fast.
On that note, IF in particular is deemed controversial as a dieting method because breakfast is noted to be the most important meal of the day. However, for weight loss (or gain), the most tried and true method is simply calories in vs. calories out. Therefore, it shouldn't matter if you're consuming your daily calorie intake over the course of 16 hours or 8 hours (as long as you're still absorbing the same amount of nutrients from the meals).
The idea of skipping breakfast in regards to IF is the effect it may have on insulin sensitivity. The more sensitive your body is to insulin, the higher possibility you have to lose fat and gain muscle. Thus, increasing insulin sensitivity tends to lead to more efficient dieting.
Insulin sensitivity is higher after the 8 (or so) hour fasting period you experience when you sleep. In particular, insulin sensitivity is greater when glycogen levels are depleted. It's common for liver glycogen to be depleted from fasting when asleep.
IF pushes your body further to the limit by extending the fasting period beyond your sleeping hours by skipping breakfast, thus further depleting glycogen, causing insulin to increase further.
Based on a 16-hour fast & 8-hour eating period, it's general practice for the fasted phase to be taken throughout the night (i.e. while asleep) and during the early hours of the morning. For example, if you were to wake up at 7 am, the fast may last another 4-5 hours, and then you would begin your eating window around noon. For the majority of people, the afternoon/evening's are usually spent in the fed state.
In saying this, it's entirely up to personal preference as to when to enter the eating window. When I was at university, I tended to fast all the way through til about 2-3 PM, since I use to work til the late hours of the night, and thus wake up later in the day.
The reasoning for fasting through the earlier part of the day, and thus eating in the afternoon/evening, is that the majority of people tend to find it easier to fast after awakening. This statement makes sense as most of us can agree that breakfast is a much easier meal to skip, as opposed to dinner, which can leave you restless if you go to bed on an empty stomach, directly affecting your quality of sleep.
Training on the Intermittent Fasting diet:
On the basis that your eating window begins around midday, if you workout in the morning you'll be doing this in a fasted state.
If your workout is going to be done on an empty stomach, it may be a good idea to take 10 grams of BCAA. This pre-workout protein intake has a stimulatory effect on protein synthesis and your metabolism. Taking BCAA will also help promote insulin sensitivity, negating the adverse effect of not having breakfast. Doing this will help you optimise your results.
Ultimately, you'd like your feeding phase to start directly after training, with the post-workout meal. However, for a lot of people this isn't feasible (i.e. the early morning gym goers), and so in this case, I'd recommend taking 10 grams of BCAA every couple of hours leading up to the time your feeding window begins.
Overall, the key things to note when undertaking the IF diet is that, as you only have a certain window of time in which you can have food, you'll want to take in 2-3 bigger meals when eating your daily calorie intake. You'll also want to eat the bulk of your calories (in particular carbohydrates) earlier in the feeding phase and slowly taper off later in the night.
It's also important to note that no calories should be consumed when you're fasting. Exceptions to this are things like coffee (preferably taken black, but you can get away with trace calories if you take milk with your coffee), tea, sugar-free gum, etc. Essentially, you're only to get away with things that have zero or trace amounts of calories, so that the benefits of fasting aren't affected.
A significant advantage of IF is that the fasting phase gives you a great window of time in which to be productive. By not having to spend time cooking and eating, you can focus on things that you need to accomplish. Doing this also enables you to keep yourself occupied and thus not think about food or your potential hunger.
It's vital to keep your feeding window constant, due to the habitual nature in which we live our lives. People tend to receive cues of being hungry around the same times each day. Therefore, maintaining a consistent routine around eating your meals will help you stick to the diet.
Finally, undertaking an IF approach to dieting doesn't mean that you can get away with eating whatever you want. First and foremost, it's imperative to supply yourself with the right amount of calories and macronutrient split that suits the goal you're trying to achieve (i.e. weight gain or weight loss). In saying this, people tend to only focus on macronutrients for dieting. However, it's crucial to meet your micronutrient requirements as well, as this will put you in the most optimal position to function at your highest capability.
If you want to get serious on your dietary requirements, I recommend going to www.freedieting.com and using their free tools to calculate the calorie and macronutrient intake necessary to meet your goals. I will also be publishing an article on micronutrients in the coming weeks, so you can learn more about why they're important and what you can do to boost your intake of them.
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