Intermittent fasting conflicts with almost every nutritional norm: eat 5-6 small meals per day; eat a healthy breakfast; don’t skip meals; don’t starve yourself; etc. With intermittent fasting (IF), you can break all those rules and still achieve the body you want.
Intermittent fasting works by increasing the times between meals to anywhere from 10, 16, to 24 hours — sometimes even more. When it comes to intermittent fasting, however, there are more myths than facts. In this article, I’ll detail the benefits of intermittent fasting, how surprisingly normal it is, and how it can help you melt fat or build muscle.
And, as someone who practices intermittent fasting regularly, I’ll also give you some tips on how to survive the fasts and thrive.
Breakfast is the first meal of the day and breaks the fast (“break fast”) that occurs between your last meal, throughout your sleep, and after you wake up.
That’s one of the reasons why breakfast is commonly touted as the “most important meal of the day” — because of your mini-fast, your insulin sensitivity (and thus your ability to favorably send nutrients between fat and muscle cells) is at its highest. The longer that fast, the higher your insulin sensitivity can theoretically get.
So what if we pushed back breakfast to increase that fast?
And with all the health benefits of fasting (which I’ll explain below), what if we manipulate our mealtimes so that we’re constantly fasting? Enter intermittent fasting.
Fast Track to Fitness
People often object to fasting because they think it’s bad for your health. There’s a lot of evidence, however, that proves otherwise.
Let’s start with Ramadan, which is the ninth and holiest month in the Islamic calendar, during which Muslims worldwide – over one billion of them – fast from sunrise to sunset. The rules? No food and no liquids. (Oh, and no ***.)
- Cardiologists in the UAE found improvements in the cholesterol of people who participate in Ramadan, which is directly correlated in risks for heart disease. In another study, levels of good cholesterol (HDL) increased by as much as 30% during the fasting period.
- Researchers in Iran also concluded that fasting during Ramadan can “help obese individuals lose weight and decrease some [coronary artery disease] risk factors.”
- Research has also been conducted on other fasting methods. During an alternate-day fasting (ADF) routine, one study saw a drop in body fat and LDL cholesterol levels — the kicker? It didn’t matter if the subjects consumed a high-fat or low-fat diet. Another study noted improvements in fat oxidation during a fast.
- In people with asthma, fasting can help improve quality of life, reduces inflammation, and increased the benefits of the medication.
- Intermittent fasting may also have benefits in slowing the aging process. Researchers found that “intermittent fasting increases lifespan and protects various tissues against disease” due to mechanisms that increase the resistance of cells to stress. In another study, subjects who alternated between 56% and 144% of daily caloric requirement had prolonged lifespans and significantly less days in the hospital.
- For cancer patients, researchers at LSU believe that using fasting as pretreatment will “improve outcomes in cancer chemotherapy, decreasing morbidity and raising cure rates.”
Hungry Hippos: Intermittent Fasting Edition
Another common objection to intermittent fasting is hunger. “Won’t I get extremely hungry?” “Isn’t it bad for you to be that hungry?” Not necessarily. Oftentimes, your hunger pangs are nothing more than habit, called the “hormonal entrainment of meals.” If you are used to eating meals at 8am, 12pm, and 6pm, the body will release hormones shortly before those times to prepare for the digestion of food — that gives you the sensation of hunger.
Fact is, we won’t starve if we go a few extra hours without food. In fact, “starvation mode” – signaled by decreased metabolic rates – don’t usually start until over 72 hours without food.
It also doesn’t affect our mental abilities. A study in the American Journal of Clinical Nutrition on people who consumed almost no calories in a 48-hour period noted “no detectable effects of calorie deprivation on any aspect of cognitive performance, ambulatory vigilance, activity, or sleep.” Fatigue was also unaffected.
Training Hungry with Intermittent Fasting
In one study conducted during Ramadan, training in a fasted or in a fed state didn’t make a difference in body composition in bodybuilders.
Researchers also found that a 3.5 day fast had minimal impairing effects on physical performance. Another study from The Journal of Physiology noted improvements in glucose tolerance (insulin sensitivity) and nutrient partitioning with fasted training.
Which Fast Should You Do?
Within intermittent fasting, there are plenty of variations – some are better suited for fat loss while others for muscle gain. Here are just a few of the dozens of IF protocols:
16-hour fast, 8-hour feeding-window. Ideally, you’ll perform workouts during your fast; after your workout, you’ll eat and that’ll be the first meal of the day.
As the name implies, Leangains is a daily IF protocol that helps you gain mass and muscle without the body fat. Berkhan recommends drinking BCAAs before your fasted workout to give you some fuel and boost your metabolism post-workout.
I use and prefer this variant of IF. Because of the flexibility in carb cycling, you can use diet for fat loss and muscle gain at the same time.
You can also eat at relatively normal times – lunch at 12pm, for example, and dinner at 7pm. That helps you maintain some semblance of a social life seeing as how the rest of the world doesn’t do IF quite yet.
24-hour fast. No feeding window – just resume a regular eating schedule on non-fast days. For a 24-hour period, don’t eat anything. Just drink water and – less ideally – zero-calorie beverages. Don’t do this more than two times a week.
Created by Brad Pilon, this form of IF is great for fat loss because, if done once a week, you’ll cut your weekly caloric intake by almost 15%. Done twice a week, you’ll shave about 29%. With such a calorie restriction, you’ll lose weight and bust through any plateaus in your fat loss. It’s also useful in re-sparking insulin sensitivity during a bulk, helping to curb the amount of fat you gain.
Eat Stop Eat is also the hardest because of the fast length. Start the fast after dinner and end it with a normal-sized dinner the next day. That way you won’t sleep hungry (which sucks). Drink plenty of water during the fast to stay hydrated and reduce hunger pangs.
An indirect benefit of Eat Stop Eat is the amount of free time you’ll have — no meals to get in the way of work. I always try to make those days the most productive.
20-hour fast, 4-hour feeding window.
Created by Ori Hofmekler, you try to get all your calories in one or two meals during that period. Unlike other IF protocols, however, you can actually eat small quantities during your fast.
On the Warrior Diet site, Hofmekler cites several studies that showed intermittent fasting significantly improved lifespan on mice, sometimes as much as 30% longer. It’s worth noting that there’s a lot of evidence of the positive benefits for IF in animal studies, but I chose not to include them. (Mainly because humans aren’t mice.) He also explains that humans are nighttime eaters and should eat as such.
19-hour fast, 5-hour feeding window.
From the website:
The long fasting period (19 hours) lets your body use stored fuel instead of fuel being delivered from digestion. That time also lets your body measure how much fat is stored and turn your appetite down if there’s too much around. With a lower appetite, weight loss becomes easy.
Intermittent fasting isn’t for everyone.
You’ll have to endure some hunger pangs in the beginning as your body gets adjusted to the new diet. You’ll have to change your eating habits. You might even get curious remarks from friends and acquaintances. If you’re not ready for those sacrifices, don’t worry — there are countless other diet options for fat loss or muscle gain.
Yet intermittent fasting also teaches a powerful lesson: eating is a privilege. The fact that we can eat whenever and however much we want to is something that we take for granted everyday.
For those interested, give it a go. I’ve been doing it for months and love it — during my fasts, I feel alert, quicker, and more-productive. I’ve been able to lose fat and build muscle at the same time. Through IF, you’ll be able to achieve a variety of physique goals — just choose the protocol that’s right for you.