Every few months, a new trend comes along in the fitness industry.
Some of them hang around a while and start to ingrain themselves in the health hierarchy, while others are no more than a fleeting fad that come and go within 6 months.
One practice that on the face of it, appeared to be a flash in the pan, but has since gone on to increase in popularity, and been embraced by a large portion of the fitness community, is fasting.
It sounds crazy – we’ve been told for so long that skipping meals is bad, and that you need to eat not just to grow, but to also support fat loss.
If that’s the case, why then, are so many people seeing success with fasting?
Types of Fasting
There are a number of ways you can employ principles of fasting in your diet.
The first (and seemingly most popular in terms of fitness, fat loss and body composition) is intermittent fasting.
This involves cramming all your meals for the day into a small window of just a few hours.
The two most used protocols tend to be Martin Berkhan’s “Lean Gains” method, where you have an 8-hour feeding window, usually having your first meal around lunchtime, and your last at around 8 or 9pm, and “The Warrior Diet,” designed by Ori Hoffmekler, which has just a 4-hour eating window each evening.
The other way you could fast is with more of a daily set up.
“Eat. Stop. Eat” by Brad Pilon embraces this concept by using 24-hour fasting periods once or twice a week.
Some people take this a step further by doing alternate day fasting, and then there are hybrid models.
The 5:2 diet for instance, involves 5 days of unlimited eating, and 2 days with a 500-calorie maximum.
In essence, there are several ways you can fast, but the one thing they all have in common is restricting the times in which you eat, which goes completely against a lot of what those of us in the fitness industry have been brought up on, reading the likes of “Muscle and Fitness” and “Men’s Health” or “Women’s Health.”
Busting the Myth
The first thing to clear up about fasting, is busting the myth that you need to eat every few hours to boost your metabolism.
This is not the case.
Your metabolism doesn’t suddenly drop from a few hours of not eating, and calorie intake actually influences metabolism far more than meal frequency.
A 500-calorie meal for instance will burn twice as many calories through metabolism and digestion than a 250-calorie meal, so eating one lot of 500 calories has no different impact on your calorie burn than eating two 250-calorie meals.
In fact, studies tend to show no drop off in metabolic rates when the same number of calories are eaten in the same time frame but spaced further apart. (1)
Why Fasting Works
There’s no magic to why fasting works, but there are several reasons why it increases dieting success for some folk.
It can make you less focused on food, and eating bigger meals helps you feel fuller.
You might just not be a morning person, and prefer to skip breakfast, have a few coffees, then grab lunch around 1 or 2pm.
Say you go to bed at 10pm, this means you’ve only got 8 hours to get in the same number of calories as you’d otherwise be spreading over 16 or so hours, which can potentially help you feel far more satiated, and less likely to snack.
Employing daily-style fasts also gives you more licence to go to town a little on the days you do eat.
While sticking to, say 500-1,000 calories on a couple of days a week will be tough, it might be worth it if that means on the 5 days you do eat, you get to eat an extra 300 to 500 over what you would were you to eat the same number every day.
When Fasting Fails
As with any dietary practice that’s a little extreme, fasting can promote a disordered relationship with diet.
Restricting food on purpose, even for just a few hours can lead to cravings and potentially binges.
Workouts can suffer too. If you’re concerned about maintaining strength and performance, it really isn’t a great idea to go into a workout having not eaten for 8 to 12 hours, then not eat again for another 3 or 4.
In the same vein, we’ve got to consider muscle protein synthesis too.
To be kept at optimal levels for anabolism, you want to spike muscle protein synthesis by consuming protein every 5 to 6 hours. Clearly you won’t be able to achieve this overnight while sleeping, but as much as possible, it’s a good idea to stick to that maximum 6-hour gap between protein feedings, which fasting doesn’t allow you to do.
Want to Fast? Go Ahead.
If fasting really does suit your personal preferences, your schedule and your lifestyle, then try it.
If it helps you to adhere to your diet better, and stick to the plan more so than splitting your meals up evenly would, then clearly, it’s a sensible choice to make, as consistency rules the day.
That said, it might be wise to make just a few tweaks.
As protein is so important, I recommend supplementing with a BCAA shake every few waking hours during a fast to help keep muscle protein synthesis levels up.
Another option is to simply go low-calorie during the day, or stick to mainly protein-based foods, and save your carbs and fats for later in the day, or around your workouts.
For instance, for someone eating 200 grams of protein, 250 grams of carbs and 60 grams of fat per day, their modified fast could look something like –
- 0700 – Wake and consume 40 grams protein, 10 grams carbs, 5 grams fat
- 1000 – 40 grams protein, 10 grams carbs, 5 grams fat.
- 1300 – 40 grams protein, 50 grams carbs, 10 grams fat.
- 1600 – Pre-workout – 40 grams protein, 90 grams carbs, 20 grams fat.
- 2000 – Post-workout – 40 grams protein, 90 grams carbs, 20 grams fat.
Remember – fasting isn’t a secret trick, or stubborn fat loss solution – it’s just a different method of dieting that might suit your personal preferences better than eating every few hours.