It might sound pretty crazy to those of us used to surrounding ourselves in the bodybuilding magazines and literature, but daily fasting diets are catching on in a big way.
It isn’t just the hippie guys and girls, or sedentary folk doing them either – people in the sports performance and body composition fields are playing around with them too.
It’s almost like the pendulum has swung completely, from the days of every single gym rat eating every 2 to 3 hours to “keep the metabolism boosted” to people going whole days (sometimes as long as 36 hours) without eating a single thing.
So is this downright madness, or is there something to it?
Let’s find out.
What is Daily Fasting & What Does it Involve?
A daily fast doesn’t involve just not eating, and there are actually several ways you can go about it.
I guess the easiest way to describe it is to firstly differentiate it from other fasting diets that don’t change your calorie intake from day to day.
Two of the most popular diets based around fasting are The Warrior Diet, which condenses all your food into a 1 to 4 hour window, and Lean Gains, which is typically a 6 to 8 hour window.
Both of these, while they are fasts, allow you to eat the same number of calories every day as you would were you eating every few hours.
Daily fasts, however, are a little different.
You might be trying something like Eat. Stop. Eat, which includes one or two 24 hour fasts every week.
The 5:2 Diet is also a recent addition to the fasting library, which has two days per week where you’re only allowed to consume 400 to 600 calories, and 5 days where calorie intake is unlimited.
Even the highly respected nutritionist Dr. John Berardi along with his colleague Nate Green experimented with daily fasts in their “Bigger, Smaller, Bigger” program.
Aside from these, you also have the religious fasting protocols, but these are outside of what we’re looking at in terms of strength, performance, muscle gain and fat loss.
What Can You Eat?
Daily fasting diets don’t really dictate what you eat, apart from the fact that on your fast days, your calories are either at zero, or severely limited.
On the non-fasting days, some diets set a calorie limit, others don’t.
Typically though, as these diets are designed for weight loss, you’re encouraged to choose “cleaner foods” first – like lean proteins, veggies, fruits, and so on.
What Would a Typical Day Look Like?
- You’d either eat nothing aside from drinking water, coffee, diet drinks, teas, and maybe some BCAAs, or, on something like the 5:2 diet, you could have one 500-calorie meal that might just be a big salad with chicken or salmon, a small serving of rice, and a couple of pieces of fruit.
If your goal is to put on strength and size, then you just need to eat!
We’re talking pancakes and eggs for breakfast, a huge steak and cheese sandwich at lunch, a burger and fries for dinner, and snacks of nuts, milk, protein bars and so on.
One or two days of virtually no calories can have a severe impact on your gains, so you need to make up for it on the other days.
For weight loss, you’d be a little more restrained, but would still need to keep protein high to mitigate any muscle loss from the fasting.
The one main benefit is that by fasting once or twice a week, you allow yourself more leeway on the days you do eat.
For some people, this can help psychologically, as you get used to the hunger on the fast days, and then enjoy bigger, more calorie-dense meals on the others.
It also teaches you what true hunger is, and can reduce cravings and eating through boredom.
If you try to train on a fast day, you’re going to have a hard time.
Even if you do manage to drag yourself to the gym and get through a workout, your performance will be impaired, and recovery will suffer.
While workout nutrition isn’t as important as some bros claim, there’s still a lot to be said for getting in solid pre- and post-workout meals rich in protein and carbs to fuel growth and recovery.
Additionally, if your diet doesn’t give any guidelines as to calorie intake on your non-fasting days, it’s easy to eat several thousands of calories over what you might usually, and push yourself into a weekly surplus, meaning you gain fat.
Should You Follow a Fasting Protocol?
I’d advise strongly against doing so unless it's going to make hitting your macros and life in general easier.
Once again, if your personal preferences and schedule really do favour a daily fasting diet, and you still eat flexibly, hitting your weekly calorie intake and tracking your macros, it is an option.
However, you simply can’t train optimally, or expect to build muscle as well as you could eating with a more “normal” meal frequency.
For fat loss?
It’s probably not quite as detrimental, but you’ll still struggle to retain muscle mass going a whole 24 to 36 hours with no protein.
Bottom line – just hit your calories and macros every day.