Do you battle with excess weight? Are you showing signs of insulin and leptin resistance? Is your fasting blood sugar above 100? If your answer is ‘yes’ to one or more of these questions, you may want to reconsider not only what you eat but also when you eat.
One lifestyle factor that seems to be driving obesity as well as many other chronic diseases is not only that we eat too much but also the fact that we eat too frequently.
Research reveals that many people eat all day long, we call that grazing. Most also consume a majority of their daily calories late in the evening, and this type of eating habits almost guarantees weight gain and metabolic dysfunction.
The reason so many people struggle with their weight (aside from eating a diet rich in processed foods and sugars) is because they rarely, if ever, skip a meal.
As a consequence, their bodies have adapted to burning sugar as primary energy source, which down-regulates enzymes that are responsible for utilising and burning stored fat. Furthermore, from an evolutionary perspective, our ancestors didn't have 24/7 access to food, and biologically our body basically isn't designed to run optimally when fed continuously.
Biological Repair and Rejuvenation Happens Whilst Fasting
We know from research that many biological repair and rejuvenation mechanisms operate when there's an absence of food, and this is another reason why all-day grazing trigger sickness. The body never has the time to get rid of the garbage and regenerate.
When you go fast for a period of time, the resulting metabolic changes stimulate a natural cleansing process known as autophagy (or mitophagy in the case of mitochondrial autophagy), in which the body detoxifies and rids itself of damaged cells.
When we are in constant "grazing” mode, the body does not benefit from any of these processes. That is not to say, though, that you need to (or should) starve yourself for extended periods of time.
Simply cycling between periods of eating and fasting on a daily or weekly timetable has been shown to provide many of the same benefits as complete fasting, where food is avoided for several days.
The Benefits of Intermittent Fasting
Intermittent fasting is a term that covers many different meal timetables. As a rule of thumb, it involves cutting calories completely or partially, either a couple of days a week, every other day, or even daily, which is my own personal preference.
Intermittent fasting is becoming increasingly popular, justifiably because it works. And it works whether you're trying to lose weight or simply improve your biomarkers for optimal health.
The reason why intermittent fasting is so effective for weight loss compared to other calorie-cutting diets which have a high failure rate has to do with the fact that the body converts food into glycogen — a form of energy that it can store for later use. The body then stores away that glycogen in both fat cells and in the liver. If you're eating all day, the stores of glycogen in the liver are never depleted.
On the other hand, after about 12 hours without food the liver runs out of glycogen, at which point the body starts drawing energy from the glycogen stored in the fat cells.
In a nutshell, our body was designed to:
a) run on fat as its primary fuel, and
b) cycle through periods of feast and famine. Today, most people do the complete opposite. They graze on sugar and net carbs (total carbs minus fibber), which is virtually identical to sugar metabolically, all day long.
Therefore, by imitating the eating habits of our ancestors, who did not have access to food around the clock, we restore our body to a more natural state that allows a whole host of biochemical benefits to take place.
Fasting May Be Beneficial to Preventing Cancer and Dementia
Apart from regulating our weight, intermittent fasting is also one of the ways to significantly boost mitochondrial health and energy efficiency, which is important for chronic disease prevention, thereby cutting the risk for health problems such as heart disease and cancer.
Intermittent fasting can also have a positive impact on brain function, and may even hold the key to preventing Alzheimer's disease.
Research on mice suggests that alternate day fasting can boost a protein known as brain-derived neurotrophic factor (BDNF) by anywhere from 50% to 400%, depending on the brain region.
BDNF activates brain stem cells to convert into new neurons. It also triggers other chemicals that promote neural health, and has been shown to protect brain cells from adverse changes associated with Alzheimer's and Parkinson's disease.
Is One Intermittent Fasting Protocol superior to others?
There are many intermittent fasting protocols to choose from, and the "right" one for you is the one you will actually manage to comply with. Here are a few of the most popular protocols. For even more fasting protocols, including ones that are specifically designed to be combined with exercise, please contact me.
5-day fasting - In one recent research, people who fasted five consecutive days once a month, over a period of 3 months, saw improvements in biomarkers for cell regeneration, as well as risk factors for diabetes, cancer, cardiovascular disease, and aging.
In this protocol, you do not completely abstain from food during these days. On the first day, you eat about 1,000 to 1,100 calories, followed by 725 calories on the remaining four days. Your diet during these days should be primarily plant-based, low in carbohydrates and protein, and high in healthy fat.
Keep in mind that it can be quite difficult to manage five full days with very little food, especially if you have no prior fasting experience, so you may want to work your way up to this kind of protocol.
5:2 fasting – In this protocol, you cut your food down to 25% of your normal daily calories on the two fasting days of your choice (usually about 600 calories for men and about 500 for women), along with plenty of water and tea. On the other five days of the week, you can eat normally.
Alternate day fasting - This protocol is exactly as its name suggests: one day off, one day on. On fasting days, you restrict your food intake to one meal of about 500 calories. On non-fasting days, you can eat normally.
When you take into account sleeping time, this fast can end up being as long as 32 to 36 hours. Some research has shown that alternate day fasting can help lose up to 1kg per week.
Another benefit to alternate day fasting is that your body tends to adapt to the regularity of the program, whereas the randomness of the 5:2 plan can be more of a challenge to adapt to. In trials, about 90% of participants are able to stick to alternate day fasting, whereas the other 10% drop out within the first two weeks.
A word of caution: more recent research shows that if you want to lose weight, you cannot binge on non-fasting days when you're on an alternate day fasting plan, which is something you can typically do on the 5:2 plan. Exactly why is still not clear, but it may have to do with the fact that there's less regularity in the pattern on the 5:2 plan, which makes it more difficult for the body to ‘predict’ and make adjustments to become more efficient.
Peak Fasting - Restrict daily eating to a six- to ten-hour window (the key here is to eat breakfast or dinner, but not both). Here you avoid eating for 14 to 18 hours. This strategy is more aggressive and, as a result, people tend to see results sooner. The specific time is based on your individual blood sugar measurements. This is my personal preference as it's really easy to comply with once the body has shifted over from burning sugar to burning fat as its primary energy source.
At that point, you stop experiencing frequent hunger sensations, and are able to go for hours without a drop in energy. Fat, being a slow-burning energy source, allows us to keep going without suffering from the dramatic energy crashes associated with metabolising sugar.
In order to make this protocol work, you need to skip either breakfast or dinner. Which one to omit is your personal choice. However, if you chose to eat dinner, it's important to avoid eating for at least three hours prior to going to sleep.
The rationale for this recommendation has to do with the way our body produces energy. When sleeping, the body needs a minimum amount of energy, and if it’s being fed at a time when energy is not required the mitochondria creates excessive amounts of damaging free radicals. Therefore, peak fasting is another important factor that can help optimise mitochondrial function and prevent cellular damage from taking place.
Even During Periods of Fasting, What You Eat is Still Important
Although several intermittent fasting programs claim that you can binge on whatever you want on non-fasting days, I strongly recommend paying attention to the quality of what you eat regardless of the protocol you choose.
Since your overall food consumption diminishes whilst on intermittent fasting protocols, you'll want to ensure that you are getting high-quality nutrients from your food. Healthy fats are especially important, as intermittent fasting pushes your body to switch over into fat burning mode. If you feel tired and lethargic, it may be an indication that you need to increase the amount of healthy fats in your diet.
Reducing net carbs (total carbs minus fibre) is just as important. Fructose is predominantly a potential problem because it activates a key enzyme, fructokinase, which in turn activates another enzyme that causes cells to accumulate fat and resist releasing it as fuel. If you're overweight, insulin-resistant, or diabetic, reducing sugar consumption is critical. So, as a general rule — whether you're fasting or not, and regardless of the fasting protocol you're using —it's important to eat a diet that is:
High in healthy fats. Many will benefit from 50% - 85% percent of their daily calories in the form of healthy fat from avocados, organic grass-fed butter, free range egg yolks, coconut oil, and raw nuts such as macadamia, pecans, and pine nuts.
Unrestricted amounts of fresh low net carb vegetables, preferably organic.
Moderate amounts of high-quality protein from organically raised, grass-fed or free-range animals. Most people ae unlikely to need more than 40 to 80 grams of protein per day. (I recommend limiting protein intake to one gram of protein per 1 kilogram of lean body mass.)
Peak Fasting — Recommended Duration
Apart from when and what to eat, another regular question is how long. While some (such as I) embrace it as a lifestyle (and this tends to be particularly true of those who restrict their daily eating to a specific window of time), it's not something you are obliged to do for the rest of your life. I don't recommend any of the other types of fasting as they have major disadvantages from a metabolic perspective (which if beyond the scope of this article).
As a general rule, I recommend a type of intermittent fasting that is called Peak Fasting, which is done every day rather than a few days a week or in a cycle. However, you can certainly include off days due to schedule or social commitments. The key is flexibility and moderation. But if circumstances allow, seek to do it every day. The protocol is quite simple.
Stop eating three hours before going to bed and don't have your next meal for at least 13 hours. Have your blood sugar measured at that time. The test should be repeated every half hour, and when it starts to dramatically rise, this is an indication that you need to break your fast and nourish. If you reach 16 to 18 hours and your blood sugar still hasn't spiked, feel free to eat if you want to.
Why is that? Spiking blood sugar when you haven't eaten is a sign that glucogenesis is setting in. By definition, glucogenesis refers to the production of glucose from a non-glucose precursor, such as protein. Once your body starts converting protein to glucose, you're breaking down your lean muscle mass, and this is counterproductive.
For that reason, I strongly recommend avoiding longer complete fasts. Research shows you can lose about 125 grams of muscle mass per day if you fast for two days or longer!
If you're overweight and/or have symptoms of insulin and leptin resistance, such as high blood pressure, high cholesterol, or full-blown type 2 diabetes, continue intermittent fasting until your insulin/leptin resistance improves, and your weight, blood pressure, cholesterol ratios, or diabetes normalises. As an example, if you need to lose 25 kg, you might consider about six months or so of intermittent fasting, after which you may go back to eating more regularly.
After that, all you need is a "maintenance program." Keep track of your markers, and if they start sliding, go back on the fasting program of your choice again for a number of weeks or months. Alternatively, you could intermittently fast for say one month, twice a year, as a form of maintenance.
If you are new to fasting, it may take some time to work up to 13 hours, but once you start activating your fat burning mechanism you it will become much easier. The most effective way is to limit your net carbs (total carbs-fibre) to under 40 grams per day and do not exceed more than 1 gram of protein per kilogram of lean body mass.
Making It Through the Transition Period the Easy Way
The toughest part of any intermittent fasting plan is getting through the first bit, which can take anywhere from 7 to 10 days. Maybe even longer for some people, depending on their individual level of insulin resistance, and other factors, like weight, blood pressure and cholesterol levels, and if they are not consistent with the fasting and fall of the wagon.
About 10% of people will complain of headaches when they first start fasting, but the biggest complaint is hunger. It may be helpful to remember that part of why you're craving food is because your body has not yet made the switch from burning sugar to burning fat as its main source fuel. As long as you're running on sugar, which is a fast-burning energy source, frequent hunger pangs are to be expected. Fat is much more satisfying, as it's a much slower-burning fuel.
Keep in mind that a diet which is high in carbohydrates severely inhibits the body's ability to produce lipase and use fat as a primary energy source. Lipase is inhibited because of high insulin levels, and insulin tends to rise in response to eating foods which are high in carbohydrates, so it's important to replace carbs with healthy fat in order to successfully make that metabolic switch-over and become an efficient fat burning machine.
Another factor that can stand in your way during the transition period is purely psychological. If you're used to grazing regularly, it may take some time to break this habit. One trick is to drink more water because very often people mistake thirst for hunger.
Peak Fasting May Be the Break You've Been Looking For
Many people are overweight and most would therefore benefit from intermittent fasting for a period of time. (With the exception of people who suffer from Adrenal-fatigue). When done correctly, weight is likely to be lost and insulin and leptin receptor sensitivity will be optimized, which is really important for improved health. Fasting will also:
Raises human growth hormone, which plays an important part in health, fitness and slowing the aging process. HGH is also a fat-burning hormone, which is another reason why fasting is so effective for weight loss.
Decreases the accumulation of oxidative free radicals in your cells, thereby preventing oxidative damage to cellular proteins, lipids, and nucleic acids associated with aging and ill-health.
Inhibits the mTOR pathway, which plays an important part in driving the aging process by increasing mitophagy and mitochondrial biogenesis.
If you wish to try intermittent fasting, pay attention to hypoglycaemic signs and symptoms, and if you suspect that you're crashing, make sure to eat something, like coconut oil. I do not recommend fasting if you're living with chronic stress (adrenal fatigue), or have cortisol dysregulation. Pregnant or nursing mothers should also avoid fasting, because babies require plenty of nutrients during and after birth, and as far as I’m aware, there's no research supporting fasting during this important period.
Even with a regular, well-rounded workout routine, you may still find it an uphill struggle to keep your body in its best shape if you’re not fully committed to changing your habits. It can be a real challenge, especially if you don’t know where to start.
If you’re truly committed to reaching your health and fitness goals, you are invited to contact me for more information on:
The best way to switch to burning fat as primary source of energy
Best high intensity exercise that boosts your mitochondrial health
How planning the time of your meals and fasting can help support your fitness goals
Your fitness goals can be a short distance away if you make the necessary lifestyle changes — and you can do it one step at a time. For your first step click here