Intermittent fasting: How and why I do it

“I don’t care whether you find what I’m doing radical, because biologically it is not extreme”

Since I was a child, at least since I can remember, I heard that breakfast is the most important meal of the day «eat breakfast like a king, lunch like a prince and dinner like a pauper». Research papers were supporting that anyone who is skipping breakfast cannot lose weight or worst, ends up gaining weight (because he is more hungry later on and consumes bigger amounts of food). 3 necessary meals then. 

Later, while I was studying in America, the protocol, especially in the fitness industry, was 5 meals per day. Skip any of these ? Say goodbye to your metabolism. Are you hungry ? The muscles that you worked so hard to gain, are definitely in a catabolic state.

So, I’ve become a slave of food. I had to wake up earlier in the morning to prepare my breakfast, my mid-morning snack that I’d take with me, etc. If 3 hours went by, hunger, nerves, losing muscles. When on the beach ? I’d pack a lunch box.

In the case of most diets, we are talking about marketing tricks. One good example ? Paleo diet, avoiding certain nutrients. Even worse ? Adding butter in the morning coffee…(yes, you heard that right).

With regards to IF, it is not just a marketing product but is instead based on valid research (like we’ll see further down), which seems very promising not only as a typical pattern alternative but as something with a lot of improvements in health markers. No, it’s not a miracle, neither is necessarily it better from a diet that someone else is following.

When I am discussing with friends and acquaintances about this topic the first reaction is a smile or a laughter. Not from joy but from awkwardness. You see the word “Fasting” instantly triggers the brain for something negative. Thoughts around hunger, deprivation, muscle loss, starvation mode !! (metabolic rate slows down) and extreme behaviours come to mind. Most people yet, don’t realise that once they stop eating at night, until the next day when they will eat breakfast they are in a fasting state, 8-12 hours usually. Hence the word breakfast in english. Break(the) fast.

Intermittent Fasting means not eating for a predefined period of time, number of hours or days, and eating the rest. There are a lot of variations. Let’s look at some of them:

PROTOCOLS

Intermittent Fasting can be divided into three subcategories: Alternate-Day Fasting, 24-hour Fasting and Time-Restricted Feeding. Examples:

1. LeanGains. This is what I’ve been following for 90% of the time this past year. In my opinion, it is the easiest and fits anyone who’s working out and doesn’t want to lose muscle. It became popular by Martin Berkhan. Men are fasting for 16 hours and eat all of their prescribed calories in a 8 hour feeding window. In regards to women, they will ideally fast for 14 hours and eat the calories they need in a 10 hour feeding window. During the fast no calorie consumption is allowed. Only water, black coffee and sugar-free drinks. Sweeteners usage like stevia are allowed. The easiest way to follow this protocol is to just skip breakfast and mid-morning snack. For example, if your last meal is at 20:00 at night you will not eat again until 12:00 at noon. This is something relatively easy for a big percentage of the population since it fits the lifestyle of most people. Many are doing it already without even realising. Others might need very small changes like removing milk or sugar in their coffee.

• EATstopEAT. This is something I’ve been applying 10% of the time. You are eating normally, as many meals as you want with the only difference being that once or twice per week you will not eat for 24 hours. What you can consume during the fast applies the same as with LeanGains. This is way harder than 16:8 despite being only one or two days. I am applying it if I don’t have time to eat lunch during the day or when I’ve eaten too much/high-calorie meals the previous day. I suggest you start with 16:8 and gradually start adding hours until you reach 24. 5:2 Fasting follows the same philosophy.

Two more categories that are not purely fasting but are based on reduced amount of food intake. 

• THE WARRIOR DIET by Ori Hofmekler.  Ori suggests small snacking with fruits and seeds during the day and one big meal at night. I don’t know how viable this is if for example your caloric needs are 3000 per day. Let’s assume that you consumed 500 calories from all the small snacks. I am sure that 2500 calories in one meal will knee most of us. Unless you are Blake Horton! This particular protocol is obviously not for you if you want to maintain your weight because it is based on under-eating. Also, from the moment that you eat in the morning, even a little, it cannot be defined as fasting.

• Alternate-day-diet. As the name might imply, in this protocol you’re eating typically for one day and the next day you’re eating 20-25% from the calories than you need. For most people this means that during the “fasting” days you will end up eating roughly 500-700 calories. The other days you’re eating maintenance calories. As you can tell, this protocol is basically designed for someone who’s goal is to lose weight. There are two reasons it is not so good for people that work out: if you don’t want to suffer from muscle loss during this protocol, the majority of your meals should contain protein. And while this can work (meals mainly consisted of protein), it might not be the most satisfying for most people. The second reason is because your workouts will suffer. Especially on the days that you’re eating less, the combination of low caloric intake and lack of carbohydrates will leave you with no energy.

BENEFITS

The physiology of fasting which we know is just the tip of the iceberg. Most research papers are in their infancy, with many of those being conducted on mice. They are nevertheless promising. 

According to research, diets based on fatty acids, fructose, and carbohydrates, usually end up having very negative effects on the subjects. Panda and his team conducted the following experiment in two groups of mice in which there was no change (no gene interference[1] , drugs etc): 

Group 1 had the majority of their calories coming from fat (around 40-60%). Quality wise, a similar human diet would have someone eating most of his calories from cheese, nachos, ice cream, pizza etc. 

Group 2 had exactly the same quality of food and calories however they could only eat that only around a specific window of time  at night. Let’s mention here that there are 11.000 research papers around the world proving that a high fat high calories diet leads to obesity.

It is strange that the mice that ate inside the 8-10 hour window did not manifest obesity. Additionally, their muscle mass increased and their fat tissue decreased and they also showed better coordination during exercise. (1)

Why is this happening though?

6-8 hours are needed to deplete liver glycogen stores. Your body will then mobilise fat and start the fatty acid oxidation (burn). Also, ketone bodies and beta hydroxybutyrate start being produced after 8-10 hours of fasting. 

On the contrary, by eating every 3 hours we use glucose for energy and for most bodily functions. Panda states that during this process we might harm some parts of the cell from the oxidative stress during metabolism. It has been found that the repair of these damages takes place during fasting. (2)

Fasting has been practised for millennia but only recent studies have shed light on it’s protective role. IF, however, does not only seem beneficial only in regards to fat loss and weight management. Some of its most important benefits are the following:

• In rodents, intermittent or periodical fasting protects from diabetes, cancer, heart diseases and neurodegenerative diseases, while in humans it helps in reducing obesity, hypertension, asthma and rheumatoid arthritis. Thus, fasting has the potential to delay aging and helps in the prevention and treatment of diseases while minimising the side effects that come with chronic dietary interventions. (3)
• Marrie noticed great improvements in blood glucose, HDL and triglycerides in the IF group and not in the group that followed a normal diet. Inflammation markers (IL-6, TNF-A, and IL-1b) reduced in IF but not in the normal diet group. (4)
• Researchers have also noticed reductions in blood pressure as well as in cholesterol in mice that were submitted in fasting. (5)
• A clinical trial showed that breast cancer patients that restricted their feeding window to 11 hours, had a 36% reduction of breast cancer relapse. (6)
• IF reprograms the T-cell population by, decreasing autoimmunity and preserving immunosuppression. The lack of incoming calories seems to remove the autoimmune T-cells and with food re-consumption, hematopoietic stem cells get activated to replace the T-cells, lymphocytes and other white blood cells. Additionally, it’s been proven that periodical fasting for 2-3 days protects mice from a variety of chemotherapy drugs. (7)
• Fasting for 3 or more days causes a 30% decrease or more of insulin and glucose circulation, as well as a rapid reduction of Insulin-like Growth Factor 1 (IGF-1), the main growth factor in mammals, which combined with insulin is associated with accelerated aging and cancer. (8)
• Martin, in a study conducted in obese individuals with medium asthma, showed that the participants that followed Alternate-Day IF lost 8% of their starting weight in an 8 week period. There was also an observable reduction in oxidative stress and inflammation markers and symptoms improvement that are associated with asthma and various other quality of life markers. (9)
• Mattson researched the protective benefits of fasting on neurons. In a 10-16 hour fasting, the body will resort to fat stores and fatty acids, which are called ketones, for energy. It’s been proven that this process enhances memory and learning, improves neurogenesis and delays brain diseases processes since it’s been proven that it repairs specific neurons in models of ischaemic strokes in mice. (10)
• IF has also been associated with autophagy. What is autophagy though? As Yoshinori Ohsumi (Nobel in physiology and medicine) explains, during fasting, cells break proteins down and other non-essential ingredients and re-use them for energy. Cells are also using autophagy to destroy incoming viruses and bacteria, sending them for recycling. 

Quoting Guido Kroemer, M.D., Ph.D.PU-PH: “Cells are using autophagy to eliminate destroyed cellular compartments. This process is believed to also go wrong against cancer, infectious diseases, autoimmune diseases and neurodegenerative disorders like Alzheimer’s and Parkinson’s. Autophagy is believed to play a role in aging”.

Autophagy is of vital importance not only for its protective effects in stress but also for maintaining cellular homeostasis in normal levels, at least partly because it mediates in removing potentially dangerous nutrients like aggregating proteins and dysfunctional mitochondria. (11,12)

It should be noted that prolonged fasting (4-5 days) is necessary in humans to reap the benefits of autophagy. 

Lastly, there’s an interesting field of study that is currently testing a variation of intermittent fasting in a specific feeding window based on our circadian rhythm (read my ebook for more about sleep and circadian rhythm). Mice who’s feeding window was restricted to 12/12 were found with the benefits below: 

• Fat loss in animals which followed a fattening diet.
• Increase in muscle mass in animals that followed a normal diet.
• Improvements in glucose tolerance and insulin sensitivity.
• Decreased inflammation, improvements in lipid profile and generally positive changes in gene expression.
• Increase in mitochondrial volume (especially in liver), increase in brown adipose tissue as well as increased production of ketone bodies. 
• Protection from mild liver disease. From a group that consumed more fats the results were very clear: 53% decrease in triglycerides.

All of the above might seem to you as insignificant and not playing a big role if we’re talking about someone that is already eating healthy, working out systematically etc. Partly, I won’t disagree. One big part of the population though is not doing the aforementioned. 

As Panda states, “most of the population has problems with quality eating after leaving home. It is very difficult to keep our diet on track outside of home however, it may be easier to be able to eat the times that we want to.”

… combining a correct diet with a restricted feeding window diet can (possibly) greatly help our health.

Back in the day, we used to eat to support our workouts and to have energy. Nowadays we work out to support how much we eat. We are working out defensively. The issue is that these two will never be equated. You will never be able to work out or move enough in order to equate what you can possibly put in your mouth. 

Lots of people have found that with this way (IF) they can manage their calories. Since you’re not going to eat for 1 or 2 days for example this automatically means that you will be able to eat more in the remaining days. If you skip your breakfast and mid-morning snack you’ll have bigger and more satisfying meals for lunch and dinner. 

However, it should be noted that according to research, IF doesn’t have significant benefits over daily caloric restriction for the purposes of body recomposition. As we know, when we’re talking about weight loss everything is about caloric balance. 

If you don’t exactly know what caloric balance is, it is about the energy you get through food and the energy you consume via your basic metabolism in conjunction with your daily activity. Any diet whose goal is weight loss, is based on this rule and whether you’re eating 2,3,4 or 15 times per day has nothing to do with your success. Thus, diet planning needs to be determined by the individual’s preferences, tolerance and athletic goals and only by him. 

Adequate protein, resistance training and appropriate weight loss rate should be the main focus when the goal is to successfully maintain (or gain) lean body mass as well as during a fall loss phase. Aragon (13)

One common fear -especially amongst fitness individuals- : “Ok, but if I don’t eat protein for that many hours won’t I lose muscle tissue?”

Finally, you probably don’t need to worry about losing muscle tissue if you follow the IF route:

“Maintaining muscle mass is one of the surprising properties of intermittent fasting.” Aragon (13)

Tinsley and his team, in the commonly known LeanGains study because he used a similar protocol, close to the 16:8 by Martin Berkhan, showed the following:

The individuals in the study trained 3 times per week with a push/pull/legs program, with 3 sets of 6-8 reps and an intensity of 85-90% of maximum effort.

Both groups (the group with the normal diet and the intermittent fasting) maintained their muscle mass. The IF group lost 1.6 kg of fat whereas there were no changes in the normal diet group. (14)

Moro found that resistance trained individuals who were following IF 16:8 lost significantly more fat (1.62 kg) compared to the group with normal diet (0.31 kg), without significant changes in lean body mass between groups. (15)

Similar results were also observed by Stole. Muscle mass was maintained with IF, even in the extreme frequency of 1 meal per day. (16)

The conclusion here is that it’s not necessary to consume protein every 2-3 hours like we often see various experts and fitness magazines and bodybuilders do. 

I’m citing some of my own body recomposition results during the time I’m following IF. The “lose fat and gain muscle” is noteworthy.

IF is not for everyone. Our body adapts, but needs it’s time. Time that some people might not want or can spend.

Personally, when I started out, it took me 5 days before I stopped wanting to commit mass murder until my first meal. You see, I was used to eating 5 meals with the first one being when I was waking up. So, as I can remember, I was very hungry in the morning. Hunger though wasn’t stopping during breakfast. It was like I was hungry every 3 hours the whole day.

If you manage to keep it for a few days, you just stop feeling hungry afterwards. Before you break the fast, there are a few moments that might be uncomfortable however at this stage you’ll find out that they don’t last long (5 mins for example) and are totally manageable. It’s almost addicting. It’s not accidental that studies found hunger suppression was higher with IF. (17)

You might be wondering what happens in regards to training. 

I was hesitant about how much energy I’ll have and how this will impact my training. For around 6 months and until last summer, most of my workouts were cross/crossfit/strength type. My average heart rate during workouts was 85-90% of the maximum. Meaning: training using resistances with a feeling of sprinting in a treadmill continuously for around 40 minutes. 

Also, it happened (due to my work hours) that my workouts were taking place around 1 hour before the end of the fast. For example, my dinner would be at 21:00. Thus my predetermined meal for the next day was 13:00 at the earliest. My workouts were taking place between 10 and 12. On an empty stomach. Only black coffee and water. No energy drinks, no Branch Chain Amino Acids (BCAA) – by the way, they’re not allowed during the fast.  

The outcome? No, I didn’t die. On the contrary, I can say that these were the best workouts of this type that I’ve ever done. If someone is thinking whether he’ll have energy to do his workout, my answer is yes (given that you’re getting the amount of carbohydrates that your two meals deserve ! More about that further below).

In conclusion, IF is something that I will continue doing. I like not being a slave of food and the timetables anymore. I’m not afraid of being in a catabolic state if I’m hungry. I don’t care if 17,18 or 20 hours went past without eating. Knowing of course that I’ll meet my caloric and macros needs. 

If you’re thinking about trying something like that you can start with the following simple steps:

1. Choose the pattern that fits you. I suggest 16:8. For starters, you don’t necessarily need to stay without food for 16 hours. It might have been a mistake that I made for myself. Start with 12:12, change it to 14:10 and end up with 16:8. Think of it like quitting smoking.  It’s easier to reduce it rather than going cold turkey. 
2. Calculate the calories and macronutrients that you need. IF is not something that one does only if he wants to lose weight. It’s not something you can do only for a while. You can keep eating this way all the time, regardless of the goal. You can find more details in my article here.
3. Customize a food menu that you like eating. 

Next challenge, extended fasting for 2-4 days !

REFERENCES

1. Chaix, Amandine, Amir Zarrinpar, Phuong Miu, and Satchidananda Panda. “Time-Restricted Feeding Is a Preventative and Therapeutic Intervention against Diverse Nutritional Challenges.” Cell Metabolism 20.6 (2014): 991-1005. Print.
2. Longo, V D, and S Panda. “Fasting, Circadian Rhythms, and Time-Restricted Feeding in Healthy Lifespan.” Advances in Pediatrics., U.S. National Library of Medicine, 14 June 2016, ncbi.nlm.nih.gov/pubmed/27304506/
3. Longo, Valter D., and Mark P. Mattson. “Fasting: Molecular Mechanisms and Clinical Applications.” Cell Metabolism, vol. 19, no. 2, 2014, pp. 181–192., doi:10.1016/j.cmet.2013.12.008.
4. St-Onge, Marie-Pierre, et al. “Meal Timing and Frequency: Implications for Cardiovascular Disease Prevention: A Scientific Statement From the American Heart Association.” Circulation, vol. 135, no. 9, 2017, doi:10.1161/cir.0000000000000476.
5. Hatori et al., “Time restricted feeding without reducing caloric intake prevents metabolic diseases in mice fed a high fat diet,” Cell Metab, 15:848-60, 2012.
6. Marinac, Catherine R., et al. “Prolonged Nightly Fasting and Breast Cancer Prognosis.” JAMA Oncology, vol. 2, no. 8, 2016, p. 1049., doi:10.1001/jamaoncol.2016.0164.
7. Di Biase, Stefano, Changhan Lee, Sebastian Brandhorst, Brianna Manes, Roberta Buono, Chia-Wei Cheng, Mafalda Cacciottolo, Alejandro Martin-Montalvo, Rafael De Cabo, Min Wei, Todd E. Morgan, and Valter D. Longo. “Fasting-Mimicking Diet Reduces HO-1 to Promote T Cell-Mediated Tumor Cytotoxicity.” Cancer Cell 30.1 (2016): 136-46. Print.
8. Fontana, L., et al. “Extending Healthy Life Span–From Yeast to Humans.” Science, vol. 328, no. 5976, 2010, pp. 321–326., doi:10.1126/science.1172539.
9. Martin, Bronwen, et al. IBS Journal of Science, U.S. National Library of Medicine, Sept. 2007, www.ncbi.nlm.nih.gov/pmc/articles/PMC2577199/.
10. Marosi, Krisztina, and Mark P. Mattson. “BDNF Mediates Adaptive Brain and Body Responses to Energetic Challenges.” Trends in Endocrinology & Metabolism 25.2 (2014): 89-98. Print.
11. Green, D. R., et al. “Mitochondria and the Autophagy-Inflammation-Cell Death Axis in Organismal Aging.” Science, vol. 333, no. 6046, 2011, pp. 1109–1112., doi:10.1126/science.1201940.
12. Mariño, Guillermo, et al. “Autophagy for Tissue Homeostasis and Neuroprotection.” Current Opinion in Cell Biology, vol. 23, no. 2, 2011, pp. 198–206., doi:10.1016/j.ceb.2010.10.001.
13. Aragon, Alan A., et al. “International Society of Sports Nutrition Position Stand: Diets and Body Composition.” Journal of the International Society of Sports Nutrition, vol. 14, no. 1, 2017, doi:10.1186/s12970-017-0174-y.
14. Tinsley, G M, et al. “Time-Restricted Feeding in Young Men Performing Resistance Training: A Randomized Controlled Trial.” European Journal of Sport Science., U.S. National Library of Medicine, Mar. 2017, ncbi.nlm.nih.gov/pubmed/27550719/
15. Moro Tatiana, et al. “Effects of Eight Weeks of Time-Restricted Feeding (16/8) on Basal Metabolism, Maximal Strength, Body Composition, Inflammation, and Cardiovascular Risk Factors in Resistance-Trained Males.” JOURNAL OF TRANSLATIONAL MEDICINE, BioMed Central Ltd., 1 Jan. 2016, research.unipd.it/handle/11577/3207917.
16. Stote, Kim S, et al. “A Controlled Trial of Reduced Meal Frequency without Caloric Restriction in Healthy, Normal-Weight, Middle-Aged Adults.” The American Journal of Clinical Nutrition, vol. 85, no. 4, 2007, pp. 981–988., doi:10.1093/ajcn/85.4.981.
17. Seimon, Radhika V., et al. “Do Intermittent Diets Provide Physiological Benefits over Continuous Diets for Weight Loss? A Systematic Review of Clinical Trials.” Molecular and Cellular Endocrinology, vol. 418, 2015, pp. 153–172., doi:10.1016/j.mce.2015.09.014.

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