Intermittent Fasting

Intermittent fasting is currently all the rage among those looking to improve their health, shed unwanted body fat, and pack muscle to their frame.

Celebrities such as The Rock, Hugh Jackman, Terry Crews, and the lead singer of Coldplay swear by the effectiveness of intermittent fasting.

But is it really a powerful approach to shaping an impressive figure? After all, eating small, frequent meals has been the go-to strategy for decades.

Well, in this article, we’ll dive into the shocking facts about intermittent fasting. You’ll learn the evidence-based truth about this fitness hype, and you’ll discover whether you can benefit from this eating style. So, buckle up and enjoy the ride!

What Is Intermittent Fasting?

Intermittent fasting – or “IF” in short – is an eating pattern based on cycles of fasting and eating. Thus, intermittent fasting doesn’t dictate what you should eat, but rather when to do so.

There are many ways you can approach intermittent fasting. One of the most popular strategies is called “Leangains”, which was developed by Swedish personal trainer and nutritionist Martin Berkhan.

Also known as the 16:8 method, it requires that you fast daily for 16 hours and consume all food in an eight-hour “feeding window.” 

Another common method is the one called “eat-stop-eat”. You fast for 24 hours once or twice a week, and on the other days you eat like you usually would. 

Intermittent Fasting for Weight Loss

For years, eating small meals frequently has been the go-to strategy for obtaining and maintaining a lean figure. 

Doctors, dieticians, and fitness “experts” have claimed that eating often keeps your metabolic rate roaring like a Ferrari and your body in fat-burning mode.

Fortunately, that’s not true. You don’t have to eat every few hours to sport an impressive silhouette.

When it comes to your metabolism, it doesn’t matter whether you wolf down all your calories in one meal or nibble on your food throughout the day – meal frequency does not affect metabolic rate [1]. 

Regarding body weight, your eating frequency has no direct influence on it either [2-6]. This is because energy balance ultimately determines changes to the number on your scale [7-9].

· You will lose weight if you consume fewer calories than you burn.

· You will gain weight if you consume more calories than you burn.

That said, your eating schedule influences your weight in an indirect way. Why? Because meal frequency has an impact on how many calories you consume.

And that’s where the weight loss powers of intermittent fasting lie. By shortening your “feeding window”, energy intake usually goes down automatically. 

For example, researchers found that skipping breakfast can reduce daily calorie intake by up to 400 calories [10-12]. (This clashes with the common belief that skipping breakfast leads to overeating later in the day.)

That’s why intermittent fasting can yield impressive results. One review found that body weight drops by 3% to 8% on average over a period of 3 to 24 weeks of intermittent fasting [13].

Besides, intermittent fasting benefits your hormonal environment by lowering insulin levels and boosting human growth hormone, which aids fat burning [14-18]. So, more of the weight you lose might come from actual fat mass.

Does Intermittent Fasting Destroy Muscle Mass?

One common counter-argument against intermittent fasting is that if you don’t eat every few hours, your body will enter a “catabolic” state, which, in turn, causes muscle loss.

Fortunately, that belief is wrong. Researchers have found that even after a 72-hour water fast, protein synthesis and muscle breakdown are not affected [19-20].

So, you don’t have to walk around with Tupperware containers, eating a meal every few hours for fear that your body will otherwise eat its own muscle tissue.

Intermittent Fasting for Gaining Muscle

As we’ve seen, a short-term fast does not cause muscle wasting. But what about gaining muscle? Is intermittent fasting an effective way to add mass to your frame?

Well, that depends. If calorie and macronutrient intake are matched, intermittent fasting does not have a direct effect on protein synthesis [21]. Therefore, it is just as effective for muscle gain as a regular eating style.

However, intermittent fasting has one downside when it comes to building muscle: due to the shorter feeding window, you might find it hard to consume enough calories. And to gain muscle, it is crucial that you maintain a positive energy balance, which means you have to ingest more calories than you burn. 

So, if you want to bulk up but have difficulties eating enough calories, intermittent fasting is not the best option for you – you’ll be better off with spreading your meals out evenly throughout the day.

But if you can maintain your daily calorie target with intermittent fasting and it fits your lifestyle, it can be effective and convenient for building muscle. 

Is Intermittent Fasting Safe?

Through the evolution, humans have developed metabolic pathways to cope with cycles of food abundance and shortage [22]. 

We are thus well adapted to going without food for a short time, and intermittent fasting is a very safe eating style. 

You might even argue that this cycle of feast and famine is more “natural” and healthy than eating frequent, small meals. 

In fact, researchers have linked intermittent fasting to many health benefits. Those include less oxidative stress and inflammation, increased cardiovascular health and cellular repair, and a boost in brain health [22-28]. 

And according to animal studies, intermittent fasting might even help prevent cancer and extend lifespan [29-32].

Impressive, isn’t it? But that doesn’t mean intermittent fasting is right for everyone. Some people should be careful with fasting or even avoid it altogether.

Individuals who are underweight are one such group. This is because intermittent fasting usually causes a decrease in food intake. So, if they practice this eating style, their weight might drop further.

People who should also be careful with intermittent fasting are those taking medications, having a history of eating disorders, or dealing with health complications such as diabetes, blood sugar control problems, and low blood pressure. 

Women should also exercise caution when doing intermittent fasting. Scientists have found that it can cause menstrual, infertility, and endocrine problems in female rats [33-34].  

While there are no human studies conducted on this, if you’re female, make sure you carefully evaluate how you respond to intermittent fasting. Ease into it and if you experience negative symptoms, stop immediately.

How to Get Started

If you want to get started with intermittent fasting, one of the most popular approaches (and an effective one) is the 16:8 method.

This style of eating involves fasting daily for sixteen hours. Throughout your fast, you abstain from all calories. (Non-caloric beverages such as coffee and tea are fine.)

Then, once your fast is over, you spread your calories out over the eight-hour feeding window. Whether you get them from two, three, or more meals is up to you. Go for what best fits your situation and preferences.

The Bottom Line on Intermittent Fasting

For decades, small, frequent meals have been the default plan of attack when the targets are boosting metabolic rate and slimming down. And while there’s nothing wrong with that approach, intermittent fasting might be more effective for losing weight.

Not because it has any magic fat-burning qualities (for the record, it doesn’t) but because a shorter feeding window can make it easier to keep your calorie intake in check. 

After all, maintaining a negative energy balance is the most important step when it comes to dropping unwanted body fat.

When packing on muscle is the end-game, intermittent fasting can also be a viable eating style although it makes it harder for some people to consume enough calories. So, if that’s the case with you, intermittent fasting is not your best bet.

All in all, consider intermittent fasting another instrument in the toolbox that can help you reach your fitness goals. It doesn’t offer any magic benefits, but it might make it easier to maintain your calorie target. 

Besides, not having to eat a meal every few hours can free up mental RAM during busy times.

References

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2. Harvie, M. N., Pegington, M., Mattson, M. P., Frystyk, J., Dillon, B., Evans, G., . . . Howell, A. (2011). The effects of intermittent or continuous energy restriction on weight loss and metabolic disease risk markers: a randomized trial in young overweight women. International Journal of Obesity, 35(5), 714-27.

3. Soeters, M. R., Lammers, N. M., Dubbelhuis, P. F., Ackermans, M., Jonkers-Schuitema, C. F., Fliers, E., . . . Serlie, M. J. (2009). Intermittent fasting does not affect whole-body glucose, lipid, or protein metabolism. American Journal of Clinical Nutrition, 90(5), 1244-51.

4. Arnal, M. A., Mosoni, L., Boirie, Y., Houlier, M. L., Morin, L., Verdier, E., . . . Mirand, P. P. (2000). Protein feeding pattern does not affect protein retention in young women. Journal of Nutrition, 130(7), 1700-4.

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20. Gjedsted, J., Gormsen, L., Buhl, M., Nørrelund, H., Schmitz, O., Keiding, S., . . . Møller, N. (2009). Forearm and leg amino acid metabolism in the basal state and during combined insulin and amino acid stimulation after a 3-day fast. Acta Physiologica, 197(3), 197-205.

21. Soeters, M. R., Lammers, N. M., Dubbelhuis, P. F., Ackermans, M., Jonkers-Schuitema, C. F., Fliers, E., . . . Serlie, M. J. (2009). Intermittent fasting does not affect whole-body glucose, lipid, or protein metabolism. American Journal of Clinical Nutrition, 90(5), 1244-51.

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30. Lee, C., Raffaghello, L., Brandhorst, S., Safdie, F. M., Bianchi, G., Martin-Montalvo, A., . . . Longo, V. D. (2012). Fasting cycles retard growth of tumors and sensitize a range of cancer cell types to chemotherapy. Science Translational Medicine, 7;4(124), 124-27.

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