The concept is not new. Humans have been fasting since time immemorial for different reasons: mental clarity, cleansing of the body, or simply because of food scarcity. In other instances, it’s done for religious reasons. Various faiths, including Islam, Christianity, and Buddhism mandate some form of fasting. It demonstrates the depth of your desire when praying for something. It shows you that you are serious enough about your prayer request to pay a personal price, like abstaining from food.
What is intermittent fasting?
Intermittent fasting is an eating pattern where you cycle between periods of eating and fasting. There are several types of IF, but they all share one commonality: instead of focusing on what you eat, you prioritize when to eat. So you only eat during a specific time, which helps your body burn fat.
Dr. Mark Mattson, a neurologist from John Hopkins University, puts it simply: “Our bodies have evolved to be able to be without food for many hours, even days, and once this happens, the body exhausts its sugar stores and starts burning fat.”
He refers to this as metabolic switching.
What are the different types of IF and how do they work?
There are several different ways to do intermittent fasting, but they are all based on choosing regular time periods to eat and not to eat. For instance, you might try eating during an eight-hour period each day and fast for the remainder. Or you might choose to eat only one meal a day, two days a week. There are many different fasting schedules.
Here are three of the most common practices:
The 16/8 Method: Also referred to as the Leangains protocol. When following this method, you design your day around a 16-hour fasting window and an eight-hour eating window. This means that on a daily basis, you will eat all your meals within eight hours and refrain for 16 hours, adjusting the schedule to whatever works for you. So, for example, you can choose to eat between 10 a.m. to 6 p.m., or 1 p.m. to 9 p.m. The only guideline to follow is to keep your schedule consistent each day. It helps balance your own hormones and gives you the best results.
I have been following this method for over a year. It took me some weeks to mentally manage those timings, but it was a smooth ride once I got the hang of it. I noticed my ability to focus increased, I was less tired after my workouts, I was sleeping better and my energy levels rose exponentially. “Fasting retrains our body to convert energy from fats, thus boosting our natural energy levels,” Dr. Benjamin Hardy accurately states.
Alternate Day Fasting: This one involves fasting every other day. This method has no time restrictions, but it does have a calorie intake recommendation. The most common way to follow this is by limiting your calorie intake by 25% on fasting days and consuming 125% on normal days. So, for example, if you need 2,000 calories to keep your energy levels, then you would eat only 500 calories on fasting days and 2500 calories on eating days. Studies show that this formula does not only help in weight loss but reduces inflammation and lowers LDL (bad) cholesterol.
The 5:2 Method: Also called the Fast Diet, this is similar to the latter in that it has the same calorie recommendations and no time restrictions. You will be fasting on two non-consecutive days and eat “normally” the other five days: Monday/Tuesday you eat as you always do and Wednesday your intake of food should be no more than 500-600 calories and so on with Thursday/Friday and Saturday you will fast. You can mix the days around depending on your lifestyle and schedule. When I say, “eat normally,” I mean eating healthy, wholefood, balanced meals, whether your goal is maintaining, losing, or gaining weight. I tried this method a few years ago, but it was not the right one for me. I dreaded those two days of being really hungry with only 500 calories, and personally, once that feeling of deprivation hits, I know I won’t keep it up.
Once you familiarize yourself with the choices, you can decide which one is for you.
How does weight loss happen with if?
When you go for set periods without food, it allows your body to properly focus on digestion and deplete your energy—or glucose—so that your metabolism will start burning your own body fat. “Keep in mind that the body fat is just excessive food energy that’s been stored; if you continue to eat more than you need, that excess energy has to find somewhere to go, and body fat will continue to increase,” writes nutritionist and author Lindsay Boyers.
Recent studies found that “fasting improved such disease indicators as insulin resistance, blood fat abnormalities, high blood pressure, and inflammation and bowel disease. In patients with multiple sclerosis, for example, intermittent fasting reduced symptoms in just two months,” writes Jane Brody for The New York Times.
Consistent benefits have been reported:
Thinking and memory: Studies discovered that intermittent fasting boosts working memory in animals and verbal memory in adult humans. Working memory is a cognitive system with a limited capacity that can hold information temporarily. It is important for reasoning and the guidance of decision-making and behavior.
Heart health: Intermittent fasting improved blood pressure and resting heart rates, as well as other heart-related measurements.
Physical performance: Young men who fasted for 16 hours showed fat loss while maintaining muscle mass. Similarly, mice that were fed on alternate days showed better endurance in running.
Tissue health: In animals, intermittent fasting reduced tissue damage in surgery and improved healing results.
But hold on... it gets better.
Recent studies show a positive link between cancer prevention and intermittent fasting.
Here is where things get really interesting for both patients and doctors. Is there a connection between fasting and cancer prevention? It’s been reported that “fasting for fewer than 13 hours per night was associated with 36% higher risk of breast cancer reoccurrence compared to fasting 13 or more hours at night. This difference was statistically significant, which means that it was likely due to the difference in fasting, not just because of chance,” according to breastcancer.org.
Another recent study shows that “a combination of fasting and chemotherapy slowed the progression of breast cancer and skin cancer. The combined treatment methods caused the body to produce higher levels of common lymphoid progenitor cells (CLPs) and tumor-infiltrating lymphocytes. CLPs are the precursor cells to lymphocytes, which are white blood cells that migrate into a tumor and are known for killing tumors,” as reported by Healthline.com. This same study noted that short-term starvation makes cancer cells sensitive to chemotherapy while protecting normal cells, promoting the production of stem cells.
This sounds too good to be true! I approached Dr. Steven Tucker with some clarifying questions.
Dr. Tucker is the founder of Tucker Medical Ptd. Ltd. He is a medical oncologist and internist specializing in treating breast and prostate cancer and is deeply passionate and knowledgeable about preventing cancer and other chronic diseases.
Unlike most physicians, Dr. Tucker incorporated advanced studies in Medical Nutrition and Energy Metabolism while attending medical school. This gave him a deeper understanding of the importance of food on health, how and when we should consume certain foods for greater benefits, what to avoid when diagnosed with specific ailments, and how to achieve and maintain a healthy weight. As a practitioner, he has been offering nutritional and metabolic support for cancer patients for more than 25 years.
Could your share your experience with the concept of fasting and its benefits for general health?
There are numerous benefits to fasting and this has been well documented for hundreds, if not thousands, of years. In today’s world, we all suffer from too much food too often. The chief source of today’s chronic diseases (diabetes, obesity, heart disease, and cancer) is rooted in food choice. Specifically, we are consuming too much-refined sugar and starch.
How about at a cellular level?
At a cellular level, fasting for extended periods induces autophagy, a form of planned cell death, and an associated rejuvenation. This is particularly impactful on stem cells that need to be induced into a regenerative cycle.
What are the main benefits of IF at a physical and mental level?
Intermittent fasting (e.g., 16:8 hours or a 5:2 weekly diet) is especially powerful when combined with a low-carbohydrate diet. The outcome is typically more energy and mental clarity due to the lack of high and low swings in blood sugar and the hormones that respond to carb-rich meals.
Would you recommend it for everyone? Who should fast? Who shouldn’t?
Generally, yes. We all fast overnight. There is no harm in extending that fast from 8-10 hours to 12-14 hours. As with all medical advice, double-check with your own doctor if you are taking medications. That caution aside, we can all benefit from skipping a meal.
For someone new to the concept, what would be your “starter kit” advice?
Skipping a meal, typically breakfast. Stay hydrated. Black coffee and unsweetened tea are fine to have in the morning but otherwise, just have your regular two to three meals a day but only between the hours of 12 p.m. and 8 p.m. (as an example). And if you make those meals low- or lower-carb, you will begin to feel the benefits right away. Also, be sure to add in some movement like a little extra walking, and be sure to get to sleep early. The more you sleep, the less time there is to eat!
How beneficial is fasting for weight loss and increased energy?
Think of it as a tool. It is beneficial for everyone, but it is not the only tool we have to help with weight loss and improving energy. Think holistically about your lifestyle goals and how food intake, sleep, and activity all play a role in creating a virtuous cycle.
Fasting seems to be a tool in preventing cancer reoccurrence. This is very interesting for many people. Could you please expand on this?
Cancer is often driven or triggered by glucose. While glucose is not the direct cause of cancer, reducing glucose levels helps reduce insulin levels. And high insulin levels are indeed a very big driver for common cancers. One classic study in women with breast cancer clearly showed that those who fasted for 14 hours overnight had a significantly lower risk of cancer coming back compared with those who did not fast overnight.
I attended one of your talks where you mentioned that both IF and a Ketogenic diet intake—a low carb, high-fat diet—could highly benefit and reduce the side effects of chemotherapy and improve its outcome. Could you briefly explain why this is so?
Hard to answer this briefly, but in short, when we deny cancer cells the glucose they are so reliant upon and give chemotherapy at the same time, there is enhanced cancer cell death. At the very same time, healthy cells, when fasting, reduce their metabolic rate, and therefore the chemotherapy does not harm them as much. So in sum, you get more benefits with less toxicity.
Please watch his very inspiring and relevant TED talk titled: “Powerful possibilities for making prevention better than the cure.” (Dr Tucker is on Twitter and contactable through [email protected] .)
Keep in mind that intermittent fasting may have different effects on different people. Talk to your doctor before you start any type of diet or fasting. Also, report unusual anxiety, headaches, nausea, or other symptoms after you start fasting.
I doubt I will ever go back to my old way of eating. I have witnessed the conclusive and beneficial results of fasting on myself and others.
Why give up on a good thing?