Intermittent Fasting

How to improve your wellbeing with intermittent fasting? People are talking a lot about intermittent fasting, for, among other reasons, losing weight and improving health.?Many studies show that it has a great effect on our body and brain and can extend one’s life. But what exactly is intermittent fasting and how does it work? The topic of intermittent fasting is very sensitive and controversial.?

This article is based on recent studies about intermittent fasting. It is written by Sonja Vlaar and Jocelyn Vlaar for educational purposes only; it does not constitute a doctor-patient relationship. If you have specific questions or concerns, we encourage you to consult a doctor or health professional to sign off that you are medically sound enough for intermittent fasting.

This article explains:

• What it is, when not to do it and how to do it
• How it influences your cell metabolism and hormonal balance
• Its benefits, recommendations, and drawbacks.?

What is Intermittent Fasting?

Intermittent fasting is an eating pattern in which periods of eating and fasting alternate regularly. So, it is more about when and how you eat, not what you eat.

Fasting was natural for many centuries. For our ancestors, it would sometimes take days to shoot an animal so that there was food. Our brain-body system is still adjusted to function without food for longer periods of time. In fact, it is more natural to have fasting periods than always eating 3 or 4 (or even more) meals per day.

In addition, fasting is practiced in many countries as a religious or spiritual ritual. For example, Ramadan for Muslims prescribes periods of fasting.?

When NOT to do intermittent fasting

It's better?not to do?intermittent fasting when you:

• are pregnant - you badly need the extra nutrients for yourself and your baby.
• want to become pregnant - it can negatively affect fertility.
• breastfeeding - you need extra nutrients for your baby.
• suffer from chronic stress - a small-scale study in women shows that a 72-hour fast increased the stress hormone cortisol. In chronic stress, the cortisol level is usually already elevated. (15 ).
• are under 18 - you are growing and need extra nutrients to grow.
• are underweight (BMI <18.5) or have an eating disorder such as anorexia.
• are a person with diabetes, intermittent fasting can be detrimental.
• take blood-sugar-lowering drugs - you run the risk of hypoglycemia due to low blood glucose.
• already have low blood sugar or clear blood sugar fluctuations - for the same reason as here before.

How does one do it?

Whether intermittent fasting is right for you is something you'll have to try to find out. There are several ways and there may be some practice that suits you.

There are several methods to practice intermittent fasting:

• Skipping a meal now and then: skip breakfast, lunch, or dinner.
• The 16/8 method: Someone only eat during an 8-hour period. For example, you allow yourself food from 12 noon to 8 pm. This creates a fasting period of 16 hours. Not eating for 16 hours means not using anything that contains calories, including milk in your coffee, or honey in your tea.
• 24-hour fast: This involves eating absolutely nothing from one time on one day to the same time the next day, one or two days a week. The other days you eat normally.
• One meal a day: Also called “OMAD” or one meal-a-day. This is a daily fast. During the day you drink herbal tea and/or water, but you can’t have milk or creamer in your coffee.
• Every other day: With this method, you alternate a day of fasting with a day of normal eating. A variant of this is that you do calorie restriction on the fasting day. You do eat, but you limit it to 500 calories or 1/4 of what you normally eat in calories.
• Long fasting: over 5 days you eat a reduced caloric intake of 500-600 calories per day and the rest of the month you use the 16/8 method.

Misconception

• 5:2 method: While some call it intermittent fasting, this I do not really consider as a form of intermittent fasting. For 5 days a week, you eat normally and on the other 2 days you eat very little (women 500 kilocalories and men 600 kilocalories per day). The 2 days don’t need to be consecutive, so for example you could do that on Wednesdays and Sundays.?

How intermittent fasting influences your body

Eating less now and then gives all your digestive organs some rest and also provide health benefits.

When you fast, all kinds of things in your body change at the cellular and hormonal levels. Your body releases hormones that make stored body fat more available to meet energy needs. Important repair processes are also set in motion and the expression of your genes changes.

The following changes take place in your body when you fast:

• The human growth hormone (HGH): The values of this can be up to 5 times higher than when you don’t fast. HGH promotes the loss of body fat and an increase in muscle mass. (1 )
• Insulin: The insulin sensitivity of your body improves, causing insulin levels in the blood to drop significantly. Lower insulin levels make stored body fat more available as an energy source. (2 )
• Cell repair: Fasting initiates all kinds of cellular processes, which ensure that the cells can better cope with severe stress and disease processes are prevented. The cells also initiate a repair process. The cells eat old and malfunctioning parts that accumulate in the cell. This is called?autophagy. (3 ,?4 )
• Gene expression: Research shows that changes occur in the function of various genes involved in longevity and protection against disease. (5 )?

These changes in hormone levels, cell function, and gene expression are responsible for the health benefits of intermittent fasting.

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Health Benefits?

A growing number of?studies, both in animals and humans, show the many health benefits of intermittent fasting. It is powerful for weight control and the health of your body and brain. It can even make you live longer. (6 )

A summary of the benefits:

• Weight loss: Intermittent fasting can help you lose weight and belly fat, when at the same time your calorie intake is lower (18 ). Because you eat less often, you often also take in fewer calories. But if you overindulge during your eating periods and eat a lot, chances are you won't lose weight. Especially when you stuff yourself with unhealthy food. The best effect has been demonstrated when you follow a Mediterranean diet.
• Insulin resistance: Intermittent fasting can reduce insulin resistance, reducing insulin levels by up to 30% and blood sugar by up to 6%. This protects against type 2 diabetes. (6 )
• Inflammation: Some studies show a reduction in the markers of inflammation, the leading cause of chronic disease. (7 )
• Heart health: Intermittent fasting may lower “bad” LDL cholesterol, blood triglycerides, inflammation markers, blood sugar, and insulin resistance - all risk factors for cardiovascular disease. (3 ,?8 )
• Cancer: Animal studies suggest that intermittent fasting may prevent cancer. (9 ,?10 ).
• Brain health: Intermittent fasting increases brain hormone BDNF and can aid the growth of new nerve cells. It increases synaptic adaptation, promotes neuron growth, improves overall cognitive function, and decreases the risk of neurodegenerative diseases. It could also protect against Alzheimer's and Parkinson's. (3 ,11 ,?12 ,?16 ).
• Anti-aging: Intermittent fasting can extend life in rats. Research on humans is still limited.?(13 )
• Long-term memory:?A study in mice shows that Intermittent Fasting in the form of every-other-day feeding is superior to daily Calorie Restriction in enhancing long-term memory performance. (17 )
• Longevity:?The same study in mice?provides evidence that this enhancement is associated with increased adult hippocampal neurogenesis and expression of the longevity gene Klotho. (17 )

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Recommendations

To benefit from the health effects of intermittent fasting,?it is important not to eat for at least 12 consecutive hours. Because you do both calorie restriction, intermittent fasting and eat differently for a longer period of time, the health effects are much greater. Only then do the glycogen stores (the form in which glucose is stored in the cells) in the body cells run out. The body then switches to draw on the body’s fat stores and produces ketones (the final product of the breakdown of fat) which it uses as fuel. According to episode 8 of the documentary series PROVEN about healing breakthroughs backed by science, long fasting makes us feel energized, not hungry anymore and we can think better when the body has switched from using glycogen to ketones.

After about 12 hours the glycogen stores - the form of stored energy from carbohydrates/sugars in your body cells - will become empty, after which your body will start burning fat and produce ketones. Depending on your lifestyle, your glycogen supply may be depleted a little later or sooner.?It is better if you can stretch it for a few more hours to about 16 hours or longer so that you burn fat for a few hours. For example, if you do not eat after 8 pm, you will have fasted for 16 hours if you have lunch the next day at 12 noon.

If you are fasting longer,?it is important not to eat or drink carbohydrates at all. Also be careful with carbohydrate-rich fruits and vegetables, such as boiled carrots or bananas. This turns on your metabolism: your blood glucose will rise, causing your body to produce insulin.

Proteins also trigger a metabolic response. The body converts proteins into glucose (also called gluconeogenesis), which produces insulin (14 ).

And when your body produces insulin, it cannot burn fat at the same time. Insulin ensures the storage of sugar in the cell, while the idea of fasting is precisely to empty the cells of stored sugar. The consequence of eating carbohydrates and proteins is that you break the fast cycle so that the effect is much less.

What you can eat, up to a maximum of 500-600 kilocalories, are fruits and raw vegetables with little carbohydrates and fat, such as coconut fat. Coconut fat is a very good source of energy, it does not affect your blood sugar level and thus the production of insulin.

And it is very important to drink a lot during the fast, such as plenty of water, green tea or black coffee. Caffeine boosts your metabolism, so great to start the day with.

Also do not use sweeteners. Although they contain no calories, it is unclear what the effect is on the production of insulin.

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Downsides

Intermittent fasting has many advantages. Still, you may experience some less pleasant side effects:

• Hunger?is the most common side effect of intermittent fasting. Usually, this comes in waves and will go away on its own. In any case, by drinking a lot of water you can better suppress the feeling of hunger. And it also helps with a rumbling stomach.
• Constipation?occurs regularly, also because you eat less. But when you suddenly eat a lot more fiber than usual, constipation or obstipation can be the result. You can use some Epsom salt (from a drugstore or pharmacy) and take it with a glass of water before going to sleep.
• Headaches?can also occur. Usually, this will pass after the first few fasts. Taking some extra salt can often help reduce the complaint.
• You may get?dizziness and heartburn. In case of dizziness, it helps to drink and to take sufficient salt. Eating a large meal too quickly after fasting can cause heartburn symptoms. Eat slowly and calmly and do not lie down immediately after eating.

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Why this article?

Science is continuously evolving, and there are many new insights about nutrition and the brain. We impossibly can keep up with them. That is why we wrote this article.

When I (Sonja Vlaar) graduated in 1983 at Wageningen University in Human Nutrition and Health, I had never heard about intermittent fasting. It wasn't until spring 2020 that I came to know about intermittent fasting. This I learned from the Neurozone??Enhanced Course for professional coaches.

Since then, I use the Neurozone??assessment for my clients. The outcomes of my Neurozone? assessment in 2020 included intermittent fasting as one of my high-impact recommendations. This made me so curious that I wanted to learn what intermittent fasting is all about; so?I started writing this article.

I periodically apply the Neurozone? assessment to myself to measure my?resilience index ?and track my behavioral interventions to improve my resilience and optimize performance.?I truly believe that our neuro-biological wellness rhythms form the fundament for any performance optimization.

COVID lockdown has stimulated many people to have a closer look at the wellness rhythms of their brain-body system.?In previous articles on LinkedIn, I shared some insights about the basic wellness rhythms of?exercise and mobility ,?silencing the mind , and?nutrition, and the brain.? More than ever we need to care for these rhythms and our mindset about the brain-body rhythms.

Connect with Sonja Vlaar or with Jocelyn Vlaar for more information