Intermittent fasting is currently one of the most popular health and fitness trends in the world. People use it to lose weight, improve health, and simplify their healthy lifestyle. Many studies show that it can have powerful effects on your body and brain, and can even help you live longer. The following is a definitive guide to intermittent fasting for beginners.
What is intermittent fasting?
Intermittent fasting is a term that refers to an eating pattern that uses cycles between fasting periods and meal periods. It says nothing about what foods you should eat, but rather when you should eat them.
Therefore, it cannot be defined as a „diet“ in the conventional sense. It is more accurately described as a „feeding pattern.“
Common methods of intermittent fasting involve daily fasts for 16 hours, or fasting for 24 hours, twice a week.
Human beings have actually lived fasting during evolution. Sometimes it was done because there was not enough food available, and also because it has been part of the major religions, including Islam, Christianity, and Buddhism.
If you think about it, you realize that our hunter-gatherer ancestors didn’t have supermarkets, fridges, or food available all year round.
Sometimes we couldn’t find anything to eat, and our bodies evolved in such a way that they were able to function without food for long periods of time. In any case, a fast once in a while is more „natural“ than constantly eating 3-4 (or more) times a day.
Bottom Line: Intermittent fasting is a term that refers to an eating pattern that uses cycles between periods of fasting and periods of meal. Today, it is very popular with the health and fitness community.
How to do an intermittent fast?
Intermittent fasting has been very popular for many years and several different methods can be used. They all involve dividing the day or week into „meal periods“ and „fasting periods.“ During periods of fasting, you eat little or nothing at all.
These are the most popular methods:
- The 16/8 method: Also called the “Lean gains” protocol, this consists of skipping breakfast and restricting your daily feeding period to 8 hours, for example, from 1:00 p.m. to 9:00 p.m. And then you „fast“ for the next 16 hours.
- Eat-to-eat: This is a 24-hour fast, once or twice a week, for example, not eating from dinner one day until dinner the next day.
- The 5: 2 diet: On two non-consecutive days of the week, you only eat 500 to 600 calories. You can eat normally the other 5 days. By eating fewer calories, all of these methods should make you lose weight, as long as they are not compensated for by eating too much more than necessary during feeding periods.
The 16/8 method tends to be the simplest, most sustainable, and easiest to adhere to. It is also the most popular.
Bottom Line: There are several different ways to do intermittent fasting. They all divide the day or week into „meal periods“ and „fasting periods.“
What Intermittent Fasting Affects Cells and Hormones?
When you fast, several things happen in your body at the cellular and molecular level. For example, your body changes hormone levels to make stored body fat more accessible. Your cells also initiate important repair processes, and change the expression of genes.
Here are some changes that occur in your body when you fast:
- Human Growth Hormone: Growth hormone levels skyrocket, increasing up to 5 times. This has fat loss and muscle gain benefits, to name just a few.
- Insulin: Insulin sensitivity increases and insulin levels drop dramatically. A low level of insulin makes stored body fat more accessible.
- Cell repair: When you fast, cells initiate cell repair processes. This includes autophagy, in which cells digest and remove old, dysfunctional proteins that build up inside cells.
- Gene expression: There are changes in gene function related to longevity and protection against disease.
These changes in hormone levels, cell function, and gene expression are responsible for the health benefits of intermittent fasting.
Bottom Line: When you fast, human growth hormone levels rise rapidly and insulin levels drop. Cells in the body also change the expression of important genes and initiate cell repair processes.
Intermittent fasting, a powerful tool for weight loss.
Weight loss is the most common reason people try intermittent fasting. By making you eat less food, intermittent fasting leads to an automatic reduction in calorie intake.
Additionally, intermittent fasting changes hormone levels to facilitate weight loss. In addition to lowering insulin and causing growth hormone levels to rise, fasting increases the release of the fat-burning hormone, norepinephrine (norepinephrine).
Due to these changes in hormones, short-term fasting can actually increase your metabolic rate by 3.6 to 14%.
Since fasting helps you eat fewer calories and also burn more calories, it causes weight loss by changing both sides of the calorie equation.
However, keep in mind that the main reason this works is that it helps you eat fewer calories overall. If you eat excessively and in massive amounts during meal periods, then you won’t be able to lose weight at all.
Bottom Line: Intermittent fasting can increase your metabolism slightly, while helping you eat fewer calories. It is a very effective way to lose weight and belly fat.
Health benefits of intermittent fasting.
Many studies have been done on intermittent fasting. These studies have shown that it can have powerful benefits for weight management and the health of your body and brain. It can even help you live longer.
Here are the top health benefits of intermittent fasting:
- Weight loss: As mentioned above, intermittent fasting can help you lose weight and belly fat, without having to consciously restrict calories.
- Insulin resistance: Intermittent fasting can reduce insulin resistance with lowering blood sugar by 3-6% and increasing insulin levels by 20-31%. This can protect against type 2 diabetes.
- Inflammation: Some studies show reductions in inflammation markers, a key factor in many chronic diseases.
- Heart Health: Intermittent fasting can lower LDL cholesterol, blood triglycerides, inflammatory markers, blood sugar, and insulin resistance. All of these are risk factors for heart disease.
- Cancer: Animal studies suggest that intermittent fasting can help prevent cancer.
- Brain health: Intermittent fasting increases a brain hormone called BDNF, and it can help the growth of new nerve cells. It can also protect against Alzheimer’s disease.
- Anti-aging: Intermittent fasting can extend the life expectancy of rats. Studies showed that fasted rats lived 36 to 83% longer.
Keep in mind that the investigation is still in its early stages. Many of the studies were small, short-lived, or conducted in animals. Many questions have yet to be answered in the highest quality human studies.
Bottom Line: Intermittent fasting can have many benefits for your body and brain. It can cause weight loss, and it can protect against type 2 diabetes, heart disease, and cancer. It can also help you live longer.
Intermittent fasting makes your healthy lifestyle simpler
Eating healthy is simple, but it can be very difficult to stick to. One of the main obstacles is all the work required to plan and cook healthy meals.
If you follow intermittent fasting, this will become easier because you won’t need to plan, cook, or clean up after as many meals as you did before.
Bottom Line: One of the main benefits of intermittent fasting is that it makes healthy eating easier. There will be fewer meals that you need to prepare, cook, and clean up afterward.
Should Women Fast?
There is some evidence that intermittent fasting may not be as beneficial for women as it is for men. There are anecdotal reports of women who had amenorrhea (their menstrual period stopped) when they started doing the AI, and returned to normal when they stopped doing it.
For these reasons, women should definitely be careful with intermittent fasting. Take it in moderation, and if you have problems like amenorrhea, stop doing it immediately.
If you have fertility issues and / or are trying to conceive, you’d better consider forgetting intermittent fasting for now. Intermittent fasting can be a bad idea during pregnancy or while breastfeeding.
Bottom Line: People who are underweight or who have a history of eating disorders should not fast. There is also some evidence that intermittent fasting can be harmful for some women.
If you have this history, then you shouldn’t go on intermittent fasting without consulting a healthcare professional first. In these cases, it can be downright damaging.
Safety and side effects of intermittent fasting
Hunger is the main side effect of intermittent fasting. You may also feel weak and that your brain is not working as well as you might be used to. This is only temporary, as it may take some time for your body to adjust to the new meal schedule.
If you have any particular medical conditions, you need to consult your doctor before attempting intermittent fasting.
This is especially important if you:
- Do you have diabetes.
- You have problems with blood sugar regulation.
- You have low blood pressure.
- You take medication.
- You are underweight.
- You have a history of eating disorders.
- You are a woman who is trying to conceive.
- You are a woman with a history of amenorrhea.
- You are pregnant or breastfeeding.
All that said, intermittent fasting has an excellent safety profile. There is nothing „dangerous“ about not eating for a while if you are totally healthy and well-nourished in general.
Bottom Line: The most common side effect of intermittent fasting is hunger. People with certain medical conditions should not fast without consulting a doctor first.
Frequently asked questions about intermittent fasting
Here are the answers to the most common questions about intermittent fasting.
- Can I drink fluids while fasting?
Water, coffee, tea, and other calorie-free beverages are fine. Don’t add sugar to your coffee. Milk and creams can be in small quantities or if you prefer, it is much better to substitute plant-based milks. Coffee can be particularly beneficial during a fast, as it calms hunger. However, do not use it as a crutch, or abuse its consumption. For best results we suggest you drink only water during your fasts. - Isn’t it unhealthy to skip breakfast?
The problem is that most of those who skip breakfast have stereotyped and very unhealthy lifestyles. As long as you make sure you eat healthy foods for the rest of the day and drink enough water during them, everything will be fine. - Can I take supplements while fasting?
However, keep in mind that some supplements (like fat-soluble vitamins) may work better when taken between meals. - Can I exercise while fasting?
Yes, fasted workouts are fine. Some people recommend taking branched chain amino acids (BCAAs) before a fasted exercise session. - Does Fasting Cause Muscle Loss?
All weight loss methods can cause muscle loss, which is why it is important that you lift some weights and maintain a high protein intake. One study shows that intermittent fasting causes less muscle loss than normal caloric restriction. - If I fast, will my metabolism slow down?
Studies show that short-term fasting actually increases metabolism. However, longer fasts (3 days or more) can suppress metabolism. - Should children fast?
That is probably a bad idea.
How to start?
Most likely, you have already done many „intermittent“ fasts throughout your life. If you’ve ever had dinner, and then slept in late and didn’t eat until lunch the next day, then that’s proof that you’ve already done a 16-hour fast. Many people actually eat this way instinctively. They just don’t feel hungry in the morning.
Many people consider the 16/8 method to be the simplest and most sustainable way to do intermittent fasting. So, it may be the most recommended if you want to start.
If you find it easy to go and feel good during the fast, then you can try moving on to more advanced fasts such as 24-hour fasts 1-2 times a week (Eat-for-Eat) or just eat 500-600 calories of 1 to 2 days per week (the 5: 2 diet).
Another proposal is to simply fast when it is convenient. Skip meals every now and then when you’re not hungry or don’t have time to cook.
There is no need to follow a structured intermittent fasting plan to get at least some of the benefits.
It is recommended that you experiment with the different approaches and find something that you like and fits into your schedule.
Conclusion: It is recommended to start with the 16/8 method, then maybe later try longer fasts. It is important to experiment and find something that fits you.
Should you try intermittent fasting?
Intermittent fasting is not something that everyone has to do. It is just one of many lifestyle strategies that can improve your health. Eating healthy foods, exercising, and taking care of your sleep are still the most important factors to focus on.
If you don’t like the idea of fasting after all, you can just skip all of this. Keep doing what works for you.
At the end of the day, there is no perfectly tailored solution when it comes to nutrition. The best diet for you is one that you can stick to in the long run.
Intermittent fasting is great for some people, but not for others. The only way to know which group you belong to is by testing it.
If you feel good about fasting and find that it is a sustainable way of eating, then it can be a very powerful tool for losing weight and improving health.
Example of 16/8 intermittent fasting what to eat and what not to eat
Begin by fasting from 7 AM to 1 PM, drinking only plain water to stay hydrated during that period.
From 1 PM to 9 PM. Start your meals that you should choose with the best healthy diet, including fruits, vegetables, whole foods such as whole grains, and free-range animal protein. Try to choose your food with organic quality. Avoid processed and sugary foods.
You can make variations of this time as well. So, you can make your own fasts seeing which schedule benefits you best. Perhaps you can have two fasting times a day doing a fast from 7 AM to 1 PM, food from 1 PM to 6 PM, and fasting from 6 PM to 10 PM, and then take your sleep hours that would go from 10 PM to 7 A.M.
Sleeping times are also important if you are doing this intermittent fasting consciously.
